Early skin-to-skin contact for mothers and their healthy newborn infants

  • Review
  • Intervention

Authors

  • GC Anderson,

  • E Moore,

  • J Hepworth,

  • N Bergman


Dr Gene Anderson, Edward J and Louise Mellen Professor, Frances Payne Bolton School of Nursing, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio, 44106-4904, USA. gca@po.cwru.edu.

Abstract

Background

Early skin-to-skin contact involves placing the naked baby prone on the mother's bare chest at birth or soon afterwards (< 24 hour). This could represent a 'sensitive period' for priming mothers and infants to develop a synchronous, reciprocal, interaction pattern, provided they are together and in intimate contact. Routine separation shortly after hospital birth is a uniquely Western cultural phenomenon that may be associated with harmful effects including discouragement of successful breastfeeding.

Objectives

To assess the effects of early skin-to-skin contact on breastfeeding, behavior, and physiology in mothers and their healthy newborn infants.

Search strategy

The Cochrane Pregnancy and Childbirth Group and Neonatal Group trials registers (December 2002), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2002), MEDLINE (1976 to 2002).

Selection criteria

Randomized and quasi-randomized clinical trials comparing early skin-to-skin contact with usual hospital care.

Data collection and analysis

Two reviewers independently assessed trial quality and extracted data. We contacted study authors for additional information. We collected adverse effects information from the trials.

Main results

Seventeen studies, involving 806 participants (mothers and babies), were included, but data from more than two trials were available for only four outcome measures. We found statistically significant and positive effects of early skin-to-skin contact on breastfeeding at one to three months postbirth [8 trials; 329 participants] (odds ratio (OR) 2.15, 95% confidence interval (CI) 1.10 to 4.22), and breastfeeding duration [6 trials; 266 participants] (weighted mean difference (WMD) 41.99, 95% CI 13.97 to 70.00). There was some evidence of improved summary scores for maternal affectionate love/touch during observed breastfeeding within the first few days postbirth [3 trials; 119 participants] (standardised mean difference (SMD) 0.73, 95% CI 0.36 to 1.11) and maternal attachment behaviour [5 trials; 211 participants] (SMD 0.76, 95% CI 0.47 to 1.04) with early skin-to-skin contact.

Authors' conclusions

Limitations included the methodological quality of the studies, variations in the implementation of the intervention and outcome variability. Early skin-to-skin contact appears to have some clinical benefit especially regarding breastfeeding outcomes and infant crying and has no apparent short or long-term negative effects.

Further investigation is recommended. To facilitate meta-analysis of the data, future research in this area should involve outcome measures consistent with those used in the studies included here. Published reports should also clearly indicate if the intervention was skin-to-skin contact and include means, standard deviations and exact probability values.

Plain language summary

Plain language summary

Skin-to-skin contact between mother and baby at birth helps breastfeeding succeed

In many cultures, babies are generally cradled naked on their mother's bare chest at birth. In some societies, babies are separated or dressed before being given to their mothers. The review showed that babies are more likely to be breastfed, and for longer if they have early skin-to-skin contact. Babies are also possibly more likely to have a good early relationship with their mothers but this was difficult to measure.

Background

Early skin-to-skin contact (SSC) is the placing of the naked baby prone on the mother's bare chest at birth or soon afterwards. The rationale for SSC comes from animal studies in which some of the innate behaviors of neonates that are necessary for survival are shown to be habitat dependent (Alberts 1994). In mammalian biology, maintenance of the maternal milieu following birth is required to elicit innate behaviors from the neonate and the mother that lead to successful breastfeeding, and thus survival. Separation from this milieu results in immediate distress cries (Alberts 1994) and "protest-despair" behavior. In rodent studies, the pups who had the least attentive contact from their mothers were the ones whose health and intelligence were compromized across the lifespan (Liu 1997; Francis 1999; Liu 2000). In humans, routine separation shortly after birth is unique to the 20th century. This practice diverges from evolutionary history where neonatal survival depended on close and virtually continuous maternal contact. SSC through sensory stimuli such as touch, warmth and odor is a powerful vagal stimulant, which among other effects releases maternal oxytocin (Uvnas-Moberg 1998). Oxytocin causes the skin temperature of the mother's breast to rise, providing warmth to the infant. Oxytocin antagonizes the flight-fight effect decreasing maternal anxiety and increasing calmness and social responsiveness. During the early hours after birth, oxytocin may also enhance parenting behaviors (Uvnas-Moberg 1998). Delivery room and postpartum hospital routines may significantly disrupt early maternal-infant interactions (WInberg 1995). The possibility of harmful effects of separation in the human neonate needs careful evaluation. Although from an evolutionary perspective SSC is the norm, separating the newborn from its mother soon after birth has now become common practice in many industrialized societies. Therefore, for the purpose of this review, SSC is considered the experimental intervention. Ironically, the experimental intervention in studies with all other mammals would be to separate mothers from their newborns.

Healthy full-term infants employ a species-specific set of innate behaviors immediately following delivery when placed in SSC with the mother (Widstrom 1987; Varendi 1998; Righard 1990; Widstrom 1990; Varendi 1994). They localize the nipple by smell and have a heightened response to odor cues in the first few hours after birth (Varendi 1994; Varendi 1997; Porter 1999). This 'sensitive period' predisposes or primes mothers and infants to develop a synchronous reciprocal interaction pattern, provided they are together and in intimate contact. These innate behaviors can be disrupted by early postpartum hospital routines as shown experimentally by Widstrom 1990 and in descriptive studies by Gomez 1998, Jansson 1995 and Righard 1990. Gomez 1998 found that infants were eight times more likely to breastfeed spontaneously if they spent more than 50 minutes in SSC with their mothers immediately after birth and concluded that the dose of SSC might be a critical component regarding breastfeeding success.

Infants who are allowed uninterrupted SSC immediately after birth and who self-attach to the mother's nipple may continue to nurse more effectively. Effective nursing increases milk production and infant weight gain (De Carvalho 1983). Meyer and Anderson (Meyer 1999) used SSC as an intervention for three infants who had not nursed successfully by 20 to 30 hours post-birth. The infants latched correctly after approximately 30 minutes of SSC suggesting that using this intervention may prevent or alleviate many breastfeeding problems.

SSC outcomes for mothers of premature infants suggest improved bonding/attachment (Tessier 1998); other outcomes are increased sense of mastery and self-enhancement, resulting in increased confidence (Affonso 1989; Affonso 1993). Outcomes such as sense of mastery and confidence are relevant because they predict breastfeeding duration (Dennis 1999). Women with low breastfeeding confidence have three times the risk of premature weaning (O'Campo 1992). Low breastfeeding confidence is also associated with perceived insufficient milk supply (Hill 1996). Less research on SSC with mothers of term infants has been conducted, but it seems unlikely that these would show different results.

In previous meta-analyses, early contact was associated with continued breastfeeding (Bernard-Bonnin 1989; Inch 1989; Perez-Escamilla 1994). Just altering hospital routines can increase breastfeeding levels in the developed world (Rogers 1997). In a Cochrane review of kangaroo mother care with infants who weighed less than 2500 g. at birth, Conde-Agudelo, Diaz-Rossello and Belizam found that 'kangaroo' mother care was associated with reductions in several clinically important adverse outcomes including nosocomial infections, severe illness, maternal dissatisfaction with the method of care, and failure to exclusively breastfeed at hospital discharge (Conde-Agudelo 2001). Improved maternal-infant attachment was also found. No differences were found in infant mortality. The reviewers noted, however, that methodological flaws in the reviewed studies attenuated their confidence in the findings.

Separation of mothers from their neonates at birth has become standard practice, despite mounting evidence that this may have harmful effects. A concurrent widespread decline in breastfeeding is of major public health concern. The purpose of this review is to examine the available evidence of the effects of early SSC on breastfeeding exclusivity and duration and other outcomes in mothers and their healthy neonates. Our intent is to examine all relevant outcomes; however, the predominant outcome investigated so far in healthy newborns is breastfeeding. Hence, our emphasis is on breastfeeding although we also will examine maternal-infant behavior and physiology. Because the focus of this review is on mothers and their healthy infants, potential effects of early SSC on father-infant attachment and resistance of the staff to this intervention are beyond the scope of this review. The mother's feelings about the early SSC intervention and her satisfaction with the birth experience are important and relevant but require more qualitative methods. The focus of this review is on randomized or quasi-randomized clinical trials used to test the effect of the SSC intervention.

Objectives

The objectives of this review are to examine whether early skin-to-skin contact (SSC) for mothers and their healthy newborn infants has any beneficial or adverse effects on lactation, maternal-infant behavior and infant physiology.

Criteria for considering studies for this review

Types of studies

All controlled trials, whether truly randomized or quasi-randomized, in which the active encouragement of early SSC between mothers and their healthy newborn infants was compared to usual hospital care. SSC cannot be implemented masked but the assessment of physiologic changes or outcome can often be carried out by individuals masked to allocation.

Types of participants

Mothers and their healthy newborn infants having early SSC starting less than 24 hours after birth, and controls undergoing standard patterns of care.

Types of intervention

Early SSC can be divided into several sub-categories.

(a) In 'birth SSC', the infant is placed prone skin-to-skin on the mother's abdomen or chest during the first minute postbirth. The infant is suctioned while on the mother's abdomen or chest, if medically indicated, thoroughly dried and covered across the back with a pre-warmed blanket. To prevent heat loss, the infant's head may be covered with a dry cap and replaced when it becomes damp. Ideally, all other interventions are delayed until at least the end of the first hour postbirth.
(b) In 'very early SSC', beginning approximately 30 to 40 minutes postbirth, the naked infant, +/- a cap, is placed prone on the mother's bare chest. A blanket is placed across the infant's back.
(c) 'Early SSC' can begin anytime during the first 24 hours postbirth. The baby is naked (+/- a diaper and cap) and is placed prone on the mother's bare chest between the breasts. The mother may wear a gown that opens in front, and the baby is placed inside the gown so that only the head is exposed. What the mother wears and how the baby is kept warm and what is placed across the baby's back may vary. What is most important is that the mother and baby are in direct ventral to ventral skin-to-skin contact and the infant is kept dry and warm.

In the future these groups may be analyzed separately. However, at present, not enough studies are available for sub-group analysis.

The duration of SSC was examined to investigate any 'dose-response' relationship. Although SSC can be intermittent, frequent separation may physiologically destabilize less vigorous infants.

Types of outcome measures

(a) Breastfeeding status (exclusivity) and duration;
(b) breastfeeding problems such as breast engorgement, infant latch-on difficulties, sore nipples;
(c) breast milk maturation;
(d) maternal bonding attachment behaviors (e.g. affectionate, proximity-maintaining and care-taking behaviors);
(e) maternal psychological changes after SSC (e.g. state anxiety, self-efficacy, parenting competence);
(f) changes in infant physiological parameters during and after skin-to-skin contact (e.g. temperature, respiratory rate, heart rate, blood glucose);
(g) behavioral changes in the infant during and after SSC (e.g. crying and grimacing);
(h) any other outcomes (e.g. hospital stay, economic data, longer term morbidity).

Search methods for identification of studies

See: Unavailable methods used in reviews.

We searched the Cochrane Pregnancy and Childbirth Group's and the Cochrane Neonatal Group's trials registers (December 2002).

The Cochrane Pregnancy and Childbirth Group's trials register is maintained by the Trials Search Co-ordinator and contains trials identified from:
1. quarterly searches of the Cochrane Central Register of Controlled Trials (CENTRAL);
2. monthly searches of MEDLINE;
3. handsearches of 30 journals and the proceedings of major conferences;
4. weekly current awareness search of a further 37 journals.

Details of the search strategies for CENTRAL and MEDLINE, the list of handsearched journals and conference proceedings, and the list of journals reviewed via the current awareness service can be found in the 'Search strategies for identification of studies' section within the editorial information about the Cochrane Pregnancy and Childbirth Group.

Trials identified through the searching activities described above are given a code (or codes) depending on the topic. The codes are linked to review topics. The Trials Search Co-ordinator searches the register for each review using these codes rather than keywords.

Details of the search strategies for the Cochrane Neonatal Group's trials register can be found in the 'Search strategies for identification of studies' section within the editorial information about the Cochrane Neonatal Group.

In addition, we searched the MEDLINE database (1976 to 2002) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, issue 4, 2002) using the terms:
1. INFANT*
2. BABY
3. BABIES
4. (NEW next BORN)
5. NEWBORN
6. NEW-BORN
7. NEONAT*
8. INFANT-CARE*:ME
9. INFANT-NEWBORN*:ME
10. MOTHER-CHILD-RELATIONS*:ME
11. MOTHERS*:ME
12. MATERNAL-BEHAVIOR*:ME
13. INFANT-BEHAVIOR*:ME
14. NEONATAL-NURSING*:ME
15. BREAST-FEEDING*:ME
16. LACTATION*:ME
17. MONITORING-PHYSIOLOGIC*:ME
18. HEART-RATE*:ME
19. RESPIRATION*:ME
20. SKIN-TEMPERATURE*:ME
21. OBJECT-ATTACHMENT*:ME
22. TOUCH*:ME
23. THERAPEUTIC-TOUCH*:ME
24. ((((((((((((((((((((((#1 or #2) or #3) or #4) or #5) or #6) or #7) or #8) or #9) or #10) or #11) or #12) or #13) or #14) or #15) or #16) or #17) or #18) or #19) or #20) or #21) or #22) or #23)
25. (CONTACT near EARLY)
26. (CONTACT near IMMEDIATE*)
27. KANGAROO
28. SKIN-TO-SKIN
29. (((#25 or #26) or #27) or #28)
30. (#29 and #24)

Additional journals were handsearched from January 1976 to December 2002: Acta Paediatrica Scandinavica, American Journal of Maternal Child Nursing, Archives of Disease in Childhood, Biology of the Neonate, British Medical Journal, Current Opinion in Pediatrics, Developmental Medicine and Child Neurology, Early Human Development, European Journal of Pediatrics, Journal of Developmental Physiology, Journal of Human Lactation, Journal of Nursing Measurement, Journal of Perinatology, Journal of Pediatrics, Journal of Tropical Pediatrics, Lancet, Neonatal Network, New England Journal of Medicine, Nursing Research, Pediatric Research and Pediatrics.

Methods of the review

Each identified trial was assessed for methodological quality with respect to (a) adequate allocation concealment, (b) method of random assignment, (c) selection bias, (d) performance bias, (e) detection bias, and (f) attrition bias. Each study was evaluated independently for inclusion in the review by two reviewers. We rejected trials without a concurrent control group (e.g. those with historical controls). We included relatively high quality quasi-randomized studies in the review. If the assignment to groups appeared to create equivalent groups, then the study was included even if a truly random process was not used for group assignment. For example, if women were alternately assigned to treatment and control groups and there was no reason to think that this should result in nonequivalent groups, that study was included. On the other hand, if assignment to groups was based on woman or provider preference, the study was excluded. Two reviewers extracted data and assessed the methodological quality of each study independently and compared results. Disagreements about study inclusion and methodological quality were resolved through discussion until a consensus was reached. We reviewed the inclusion criteria and therapeutic interventions for each trial to see how they differed between trials. We examined the outcomes in each trial to see how comparable they were between studies. We contacted investigators (if possible) to obtain information about any missing data. For categorical data, 2 x 2 tables were made from each trial for each important outcome, and odds ratios with 95% confidence intervals were used in the meta-analysis. For continuous variables, weighted mean differences (WMD) with 95% confidence intervals were calculated.

Description of studies

Seventeen studies with 806 women met the inclusion criteria. None of the 17 studies met all of the methodological quality criteria. Of the 17 studies, 16 were randomized controlled trials and one study (Anisfeld 1983) was quasi-randomized (group assignment by day of the week). Anisfeld 1983 stated that the groups were similar in socio-economic and medical characteristics. Mothers delivered vaginally in 15 of the 17 studies. Shiau 1997 included some women who had caesarean births (12 of 58). All the mothers in McClellan 1980 delivered by caesarean section.The total sample sizes in the studies ranged from eight to 68 mother-infant pairs. The studies represented very diverse populations in Canada, Guatemala, Spain, Sweden, Taiwan, and the United States. All but one of the 17 studies included only healthy fullterm infants. One study (Syfrett 1996) was done with healthy preterm infants (mean gestational age 34.8 weeks, mean weight 2307 g), who were assigned to the normal newborn nursery. A large number of outcomes (40) were utilized in the analysis but only a few outcomes (11) included multiple trials. Details of each included study are in the table of 'Characteristics of included studies'.

Fifteen studies were assessed and excluded from the review. The primary reason for exclusion was that the investigators did not state that the infants in the intervention group received early skin-to-skin contact with their mothers. When the information in the research report was unclear, the investigators were contacted, if possible, to determine whether the early contact was indeed skin-to-skin (see the table of 'Characteristics of excluded studies'). At the time of writing, five studies are still awaiting assessment; three of these studies (Villalon 1992; Villalon 1993; Mazurek 1999) require translation.

Methodological quality

The overall methodological quality of the included studies was considered marginally adequate. The two most problematic areas were allocation concealment and provider performance bias. In 12 of the 17 studies, not enough information was provided to determine if the method of random assignment was robust before allocation of the participants to groups occurred. In three studies (De Chateau 1977; McClellan 1980; Anisfeld 1983), allocation concealment was clearly inadequate. Only two studies (Syfrett 1996; Shiau 1997) provided enough information to determine that allocation concealment was controlled by using a computer program to assign women to groups (the minimization method). Although the Syfrett 1996 study was small (N = 8) the recruiter was naive to the minimization method of random assignment. In six studies (Hales 1977; Carlsson 1978; Thomson 1979; Svejda 1980; Christensson 1992; Christensson 1995), the researchers indicated that women were randomly assigned to groups but no further information was provided about the randomization method. In five studies (Sosa 1976a; Sosa 1976b; Sosa 1976c; Craig 1982; Curry 1982), sealed envelopes were used but the investigators do not state whether the envelopes were sequentially numbered or opaque.

None of the research reports stated that the delivery and postpartum staff were unaware of the group assignment of the mothers. Therefore, control for provider performance bias was difficult to determine. In the three studies that evaluated infant physiological outcomes (Fardig 1980; Christensson 1992; Syfrett 1996), however, patient or provider performance bias would not be as significant an issue as it might be with maternal attachment and breastfeeding outcomes. Surprisingly, patient performance bias was more adequately controlled. In five studies (Carlsson 1978; Thomson 1979; Svejda 1980; Craig 1982; Curry 1982), the women were not aware that they were receiving an experimental treatment and/or they were not informed about the true purpose of the study. Adequate control for patient performance is problematic in the more recent studies because of Institutional Review Board requirements that investigators disclose the true purpose of the study and/or the experimental conditions.

Detection and attrition bias were the threats to validity that were most adequately controlled. In 10 of the 17 studies, outcome assessors (whenever possible) were not aware of the woman's group assignment. In several studies, when infant physiological or crying data were obtained by observation during SSC (Fardig 1980; Christensson 1992; Christensson 1995; Syfrett 1996), the outcome assessors could not be masked. In all but one study (Carlsson 1978) outcome data were either obtained on all the enrolled women or reasons were provided for women who withdrew or had to be withdrawn.

Results

Sixteen of the 17 studies reviewed were randomized controlled trials. Forty clinical outcomes were included although only 11 were measured by more than one study. The results of heterogeneity of the analysis using more than one study were significant for three outcomes: breastfeeding duration in days, affectionate love touch during a breastfeeding 36 to 48 hours postbirth, and mother kissing infant during a play observation three months postbirth. The analysis of the studies for the remaining eight outcomes were all non-significant for heterogeneity.

Breastfeeding outcomes were measured in eight studies (Sosa 1976a; Sosa 1976b; Sosa 1976c; De Chateau 1977; Carlsson 1978; Thomson 1979; Syfrett 1996; Shiau 1997). Early SSC resulted in statistically significant and better overall performance on all measures of breastfeeding status (using the Index of Breastfeeding Status (Labbok 1990; Cadwell 2002)), and duration. No between-group differences were noted in maternal chest circumference (measured in centimeters across the nipples) three days postbirth (Shiau 1997). Breast engorgement pain (measured by the self-reported Six Point Breast Engorgement Scale (Hill 1994)) was less for SSC than non-SSC mothers on day three postbirth (weighted mean difference (WMD) -0.80, 95% CI -1.46 to -0.14) (Shiau 1997). No between-group differences were found in breast milk maturation (Shiau 1997), that is, progression from colostrum to mature milk (measured by the Maturation Index of Colostrum and Milk, (Humenick 1994)). More SSC dyads were still breastfeeding one to three months (30 to 90 days) postbirth (odds ratio (OR) 2.15, 95% confidence interval (CI) 1.10 to 4.22) This meta-analysis included all eight studies that contained breastfeeding outcomes and involved 329 mother-infant pairs. In six of the eight studies, SSC dyads were more likely to be breastfeeding one to three months postbirth although the difference reached statistical significance in only two studies (Sosa 1976c; Thomson 1979). One study (Carlsson 1978 ) found no differences between-groups. In one study (Sosa 1976a), women in the control group were more likely to breastfeed one to three months postbirth. These investigators speculated that their findings might be explained by the fact that more women, who had recently come from rural areas, where breastfeeding was common, were in the control group. Apparently simple random assignment was not effective on this potentially confounding variable. In two studies combined (De Chateau 1977; Shiau 1997) (n = 62), more SSC dyads were breastfeeding at one year (OR 7.62, 95% CI 0.89 to 65.23), however, this analysis did not reach statistical significance (p = 0.06). Six studies also obtained data on the duration of breastfeeding in days. Five of the six studies (De Chateau 1977; Sosa 1976b; Sosa 1976c; Syfrett 1996; Shiau 1997) found a longer duration of breastfeeding in the SSC dyads (WMD 41.99 days, 95% CI 13.97 to 70). Again Sosa 1976a found that women in the control group breastfed longer than those in the intervention group in one of their three studies. This analysis must be interpretated with caution, however, because of the inflation of standard deviations in several studies due to the long duration of breastfeeding for some of the mothers.

The characteristics of the intervention varied greatly between studies. Duration of SSC ranged from approximately 15 minutes (De Chateau 1977; Thomson 1979) to a mean of 37 of 48 hours (84%) of continuous SSC (Syfrett 1996). Although SSC began by 10 minutes postbirth in seven of the eight studies, the SSC dyads in the study by Shiau 1997 could not begin until four hours postbirth because of hospital policy. In all eight studies, the infants were given the opportunity to suckle during SSC but only Thomson 1979 and Syfrett 1996 documented how many infants actually nursed during their first breastfeeding attempt. The amount of assistance the mothers received with breastfeeding during SSC is unclear in many of the research reports. Assistance with the first breastfeeding may be a necessary component of SSC because many mothers are often very insecure about their ability to successfully initiate breastfeeding. Substantial differences were found between studies in the amount of mother-infant contact provided in the control group. In four studies (Sosa 1976a; Sosa 1976b; Sosa 1976c; Shiau 1997), infants were removed from their mothers immediately postbirth and reunited 12 to 24 hours later. In two studies, the mothers held their swaddled infants for about five minutes soon after birth. In Syfrett 1996 all dyads received 24 minutes of SSC before randomization. Only Syfrett 1996 provided any information about when the control infants first breastfed or how effectively they nursed.

Although four studies examined infant temperature outcomes (Christensson 1992; Christensson 1995; Fardig 1980; Syfrett 1996), the studies used different modalities and time-frames. Abdominal, interscapular and axillary temperatures, rather than rectal temperatures, were used in the meta-analysis because skin temperatures are considered to be the most accurate reflection of fluctuations in environmental temperatures according to Fardig 1980. Only Fardig 1980 obtained rectal temperatures. Christensson 1992 and Christensson 1995 did not obtain rectal temperatures because they were measuring infant crying outcomes. Syfrett 1996 did not obtain rectal temperatures because the procedure would be stressful for the infants.

Fardig 1980 obtained data on the number of infants with abdominal skin temperatures in the neutral range after 21 and 45 minutes of SSC. SSC infants were placed on the mother's bare chest and covered with three prewarmed cotton blankets. Control infants were swaddled in warm blankets and given to their parents to hold if requested or remained under the radiant warmer. Fardig 1980 defined neutral thermal range as abdominal skin temperatures of 36 to 37.5 degrees centigrade. At 45 minutes postbirth, more SSC infants had abdominal skin temperatures in the neutral thermal range (OR 12.18, 95% CI 2.04 to 72.91). In the studies by Christensson 1992 and Christensson 1995, infants had SSC or were placed in a 'cot' (bassinet) next to the mother during the first 90 minutes postbirth. Neither group of infants were fed. Christensson 1992 obtained infant axillary temperatures after 90 minutes of SSC and found that SSC infants had a mean skin temperature of 37.1 compared with 36.7 in the cot control group. Christensson 1995 found that SSC infants had a mean skin temperature of 36.9 compared with 36.4 in the cot control group. Meta-analysis of these two studies resulted in a WMD of 0.43 degrees (95% CI 0.25 to 0.60) favoring the SSC group. Similar results were obtained by Syfrett 1996. Mean hourly axillary temperature was 37 in the SSC infants and 36.7 in control infants (WMD 0.30 degrees, 95% CI 0.22 to 0.38). This difference was statistically significant (p < .001). Syfrett 1996 also found that SSC infants had significantly less temperature variability around their temperature mean. Their temperatures were more likely to remain in the neutral thermal range (defined as 36.5 to 37.5 degrees centigrade). All infant temperature results were statistically significant.

SSC ended at 90 minutes in Christensson 1992, and all infants were placed on an examination table to record heart rate and respiratory rate. In addition, a heelstick capillary sample was collected for blood glucose and blood gas analysis. Blood glucose was higher in SSC infants (WMD 11.07 mg/dl, 95% CI 3.97 to 18.17). Base excess (defined as the difference between cord blood and 90 minute values) was higher in SSC infants (WMD 1.60 mmol/L, 95% CI 0.13 to 3.07). Mean heart rate and respiratory rate were lower in the SSC infants at 90 minutes postbirth. Mean heart rate was 136.6 in the SSC infants; 140.7 in the cot control infants (WMD - 4.10 BPM, 95% CI -8.55 to 0.35). Mean respiratory rate was 44.3 in the SSC infants and 49.8 in the cot control infants (WMD -5.50 RPM, 95% CI -10. 56 to -0.44). All results, except infant heart rate, reached statistical significance.

A large between-group difference in infant crying was found. Christensson 1992 found none of the18 SSC infants were crying at 60 minutes postbirth compared to 10 of the 18 control infants (OR 29.95, 95% CI 1.57 to 572.87). Christensson 1995 found that 12 of the 14 SSC infants cried no more than one minute during the 90 minute observation compared to only one of the 15 control infants (OR 21.89, 95% CI 5.19 to 92.30).

Maternal attachment behaviors were analyzed in eight studies (De Chateau 1977; Hales 1977; Carlsson 1978; McClellan 1980; Svejda 1980; Craig 1982; Curry 1982; Anisfeld 1983) . Several researchers obtained data on a number of discrete behaviors such as enface, kissing, smiling, holding and encompassing (De Chateau 1977; Curry 1982). Other researchers obtained summary scores of maternal affectionate, proximity maintaining and care-taking behaviors (Hales 1977; Svejda 1980) or affectionate contact alone (Anisfeld 1983). In one study, summary scores of contact and non-contact behaviors were obtained (Carlsson 1978). In another study one summary score for maternal holding, touching and enface behavior was obtained (McClellan 1980). The context for measuring these variables varied greatly, taking place during breastfeeding, a play observation or a physical exam. Timing for measurement of these variables ranged from 36 hours to one year postbirth. This variability in instruments used, context and timing made it extremely difficult to combine many of the outcomes for meta-analysis. Duration of SSC ranged from 15 to 60 minutes in this group of studies. In three studies (Hales 1977; McClellan 1980; Anisfeld 1983), control mothers were given a brief glimpse of their infants and then the infants were transferred to the newborn nursery. In four studies, control mothers held their swaddled infants from three to five minutes (Carlsson 1978; Svejda 1980; Craig 1982) to 35 minutes (Curry 1982).

Summary scores for affectionate contact during breastfeeding 36 to 48 hours postbirth were obtained in two studies (Hales 1977; Anisfeld 1983). Curry 1982 also obtained a score for maternal affectionate love touch in her study. In a meta-analysis of these three studies, SSC increased the amount of maternal affectionate behaviors (standardized mean difference (SMD) 0.73, 95%CI 0.35 to 1.11); Svejda 1980 found only marginal differences in maternal affectionate behaviors during breastfeeding at 36 hours. Mean frequency of affectionate behaviors was 38.54 for SSC infants and 36.87 for control infants. These results could not be added to the meta-analysis, however, because neither standard deviations nor specific levels of significance for the results were provided in the research report. SSC also increased the frequency of maternal contact behaviors during breastfeeding at two (WMD 47.07, 95% CI 7.65 to 86.43) and four (WMD 59.23, 95% CI 21.72 to 96.74) days postbirth (Carlsson 1978). McClellan 1980 found that SSC increased summary scores for maternal holding, touching and enface behavior during a feeding on postpartum day one or two (WMD 28.40, 95% CI 9.25 to 47.55) and 28 to 32 days postbirth (WMD 19.90, 95% CI 10.86 to 28.94). The overall effect size of the summary scores for affectionate and contact behavior was not inflated because both non-significant and positive findings on a number of discrete behaviors were combined to obtain the summary scores. All of these results reached statistical significance.

Some of these results (maternal affectionate love-touch, contact behavior, and the summary score for maternal holding, touching and enface behavior) were combined into an overall measure of maternal attachment behavior again favoring the SSC group (SMD 0.76, 95% CI 0.47 to 1.04). The attachment outcomes were measured in frequencies during a consecutive series of 15 second maternal behavioral observations with 30 to 45 seconds allowed for recording the data on a code sheet between the observations. Total observation time varied from 10 to 15 minutes. Individual scores for the discrete behaviors (such as touching the infant) were obtained for each woman by adding the frequency scores for the specified time frame. Summary scores were obtained by adding the scores for the discrete behaviors.

The effects of early SSC are attenuated over time. Data were obtained on two discrete affectionate behaviors (enface and kissing the infant) during a play observation three months postbirth in two studies (De Chateau 1977; Curry 1982) and their results were combined for meta-analysis. Early SSC increased the amount of maternal enface (SMD 1.75, 95% CI 1.06 to 2.43) but did not increase the amount of kissing behavior (WMD 0.23, 95% confidence interval (CI) -0.16 to 0.61) at this time. De Chateau 1977 also examined the amount of maternal affectionate touching and positive holding during an infant physical exam at one year postbirth. Only slight, but statistically significant, differences were found between the SSC and control groups in affectionate touching (WMD 0.85, 95% CI 0.09 to 1.61) favoring the SSC group. SSC still increased the amount of positive holding (WMD 1.50, 95% CI 0.51 to 2.49). SSC marginally increased maternal scores on the Neonatal Perception Inventory (WMD 1.90, 95% CI 0.15 to 3.65) at day one or two postbirth (McClellan 1980) but had no effect on maternal scores on the Neonatal Perception Inventory on days 25 to 32 postbirth (WMD 0.40, 95% CI -1.25 to 2.04) (McClellan 1980; Craig 1982). Results need to be interpreted with caution in the analyses utilizing the results from the De Chateau 1977 study (holding, encompassing during breastfeeding, and kissing the infant during a play observation) as the standard deviations are greater than the mean in the control groups, thereby violating the assumptions of the analytic method.

A link may exist between maternal affectionate behaviors observed after SSC and breastfeeding success. In the study by Thomson 1979, an observer recorded whether the mothers had a happy reaction to their infants, defined as smiling, touching, looking en-face and verbalizing to the infant. A lack of reaction was defined as exhibiting few of these affectionate behaviors following the delivery room experience. The eight mothers (two SSCs and six controls) who did not have a happy reaction to their infants were not breastfeeding two months postbirth. Thirteen of the 15 SSC mothers displayed a happy reaction to their infants; however, only nine of the 15 control mothers had a happy response.

In summary, the results of this review demonstrated a statistically significant effect on breastfeeding status at day three and 28 postbirth, breastfeeding at one to three months postbirth, breastfeeding duration, maintenance of infant temperature in the neutral thermal range, infant crying, infant blood glucose, summary scores of maternal affectionate love touch and contact behavior during breastfeeding within the first few days postbirth all favoring the SSC group. Between-group differences favoring SSC mothers were noted in enface behavior during a play observation at three months and holding the infant positively during a physical exam at one year. No significant negative effects of early SSC were found during this review.

Discussion

Of all the outcomes reviewed, breastfeeding appears to be the most clinically significant. Mothers of SSC infants were twice as likely to be breastfeeding one to three months postbirth than mothers in the control groups. Infants in the SSC group breastfed an average of 42 days longer than those in the control group. The positive results in this review were obtained in diverse countries and among women of low and high socioeconomic class. In the two studies with the highest odds ratio of breastfeeding one to three months postbirth (Thomson 1979; Syfrett 1996), the researchers stated that most of the infants suckled during the SSC intervention. Effective suckling may be a critical component of this intervention in regards to long term breastfeeding success. Timing may also be critical as most healthy fullterm infants will spontaneously grasp the nipple and begin to suckle by approximately 55 minutes postbirth. During the first 30 minutes postbirth, they may only lick the nipple. After the first two hours postbirth, they often become sleepy and difficult to arouse. Also, because many primipara are so insecure during their first breastfeeding attempt, the intervention may be more successful if a clinician provides initial breastfeeding assistance as part of the intervention.

The clinical significance of the physiological outcomes (except for blood glucose) for healthy infants is debatable. Infants in the SSC group were less than one degree warmer than control infants. Their heart rate was four beats per minute slower and their respiratory rate was six breaths less per minute, on average. The heart and respiratory rates were obtained after the infants were removed from SSC and placed on an examining table (Christensson 1992). It is possible that moving the infants from their mother's chests to an exam table resulted in an increase in heart and respiratory rates. More definitive results might have been obtained if these measures were taken during SSC. It can be said with certainty, however, that early SSC is a safe intervention for healthy infants and that it does increase thermal stability and blood glucose.

The large between-group difference in the amount of crying is certainly clinically significant. Anderson 1989 proposed an evidence based rationale that maternal-infant separation is associated with excessive infant crying and can be harmful. Crying re-establishes portions of the fetal circulation. Each cry cycle causes a bolus of desaturated venous blood to shunt through the foramen ovale into the systemic circulation instead of the lungs, creating hypoxemia. This may possibly result in delayed closure or permanently patent foramen ovale. Anderson 1989 further proposes that crying causes increased and fluctuating cerebral blood flow, cerebral blood flow velocity, intracranial pressure, increased risk of intraventricular hemorrhage in preterm infants, and wasted calories meant for growth. Consequences for healthy full term infants are unknown.

The results of this analysis indicate that SSC may affect maternal attachment behaviors although these results appear to be attenuated over time. A dose-response relationship may exist as well. In the two studies with no significant between-group differences in attachment behaviors (Svejda 1980; Curry 1982), the swaddled control infants were held by their mothers for five to 35 minutes. In four (Hales 1977; Carlsson 1978; McClellan 1980; Anisfeld 1983) of the five studies with statistically significant results favoring SSC, control mothers were given only a glimpse of their infants immediately postbirth. Probably the act of holding the infant (swaddled or in SSC) soon after birth primes the mother to exhibit more affectionate contact behaviors early postpartum. Therefore, a very small dose of the intervention may be all that is necessary and the early contact (either swaddled or SSC) may be the critical component of the intervention. These findings would make sense from the perspective of early evolution where human mothers would be expected to form a rapid attachment to their infants to protect them from predators and to provide the high level of parental care necessary for such physiologically immature newborns. However, no information was provided in any of the studies about how many infants in the SSC group breastfed or how effectively they nursed. Breastfeeding during SSC stimulates the hormones such as oxytocin that promote maternal attachment and proactin which promotes lactation and, at least in rodents, maternal behavior. Breastfeeding may enhance the effectiveness of this intervention. Mothers would logically nurse their infants soon after birth in early human evolution. Therefore, one of the intervention's essential components (breastfeeding) appears to be missing in these studies. Early, effective breastfeeding while in SSC may increase the strength of this intervention with respect to maternal attachment outcomes.

The two studies with impoverished women (Hales 1977; Anisfeld 1983) had statistically significant differences in affectionate contact behaviors favoring the SSC group. The four studies with middle class women had mixed results (two with positive results favoring SSC (Carlsson 1978; McClellan 1980) and two with insignificant results (Svejda 1980; Curry 1982). Svejda 1980 speculated that middle class mothers may exhibit a ceiling effect for maternal responsiveness.

No negative outcomes were reported in any of the studies except Sosa 1976a who reported a longer duration of breastfeeding in the control group. (Given the numerous analyses and outcomes considered, one could likely attribute this isolated result to Type 1 error.)

The presently available evidence has a number of limitations.

1. Design limitations:
Of the 17 studies reviewed, 16 were randomized trials. One study was quasi-randomized (Anisfeld 1983) because assignment to groups was based on day of the week. In only two trials (Syfrett 1996; Shiau 1997) was allocation to groups adequately concealed from the investigators.

2. Outcome variability:
Meta-analysis was limited in this review due to the numerous outcomes and the limited number of randomized trials that could be included for each outcome. Although many of the studies measured similar outcomes, the outcomes were too dissimilar to be included in a meta-analysis. In some studies means were reported without standard deviations. In addition, the instruments used, context and timing of the measurement of attachment and temperature outcomes varied greatly among studies. Breastfeeding was measured as a dichotomous variable in some studies or as an interval level measure of breastfeeding exclusivity in one study. Modality for measurement of temperature outcomes varied between studies. These contextual and measurement differences should be noted when considering the results of the review.

3. Long term outcomes:
Two randomized controlled trials included long-term breastfeeding and attachment outcomes. SSC had a positive effect on long-term breastfeeding (De Chateau 1977; Shiau 1997) and little or no effect on long-term attachment (De Chateau 1977). No negative long-term outcomes were found.

Authors' conclusions

Implications for practice

The main results of the meta-analysis, and from the single studies, indicate that SSC has a positive effect on long-term breastfeeding. Although a number of the infant physiological and attachment outcomes demonstrated little or no clinically significant differences with or without SSC, no negative short or long-term effects were found. Based on the available evidence, SSC appears to have some clinical benefit, especially for breastfeeding. The timing of the intervention may be important because most infants are very alert in the first two hours postbirth and, if undisturbed and unmedicated, will self-attach correctly to the nipple at approximately 55 minutes postbirth. The temperature of a healthy newly delivered infant will remain in a safe range provided ventral-to-ventral SSC is uninterrupted and the infant is thoroughly dried and covered across the back with a prewarmed blanket and the head is kept covered with a dry cap.

Implications for research

Future investigations are recommended because the methodological quality of the included studies is marginally adequate, the characteristics of the SSC and control conditions are diverse and many outcome measures are difficult to combine. Only one study (Syfrett 1996) examined the effects of early SSC on preterm infants who were judged healthy enough to remain on the postpartum ward. The effects of this intervention may be different in this more vulnerable population and more research is definitely indicated. More research needs to be conducted on the effects of early SSC on mothers who deliver by caesarean birth. To facilitate meta-analysis of the data, future research in this area should involve outcome measures consistent with the best measures used in previous studies or measures developed recently to increase methodological rigor.

Suggestions for improvement of clinical trials examining early SSC and breastfeeding outcomes include the following. The mother's prenatal breastfeeding intention (how long she planned to nurse her infant) was not controlled in any study. Only Shiau 1997 used breastfeeding status (Labbok 1990) to measure the degree of breastfeeding exclusivity. In all the other studies, breastfeeding was considered a dichotomous variable. Only Syfrett 1996 and Thomson 1979 stated if the infant breastfed successfully during SSC. Importantly only Syfrett 1996 provided any information about breastfeeding initiation in the control group or continued SSC into the second critical hour postbirth when infants are most likely to suckle effectively. A valid measure of effective suckling at a single feeding remains elusive (Riordan 1997) and is needed to identify problems in time to minimize breastfeeding attrition; this would be a major contribution to the field.

Improvement is needed as well for examining maternal attachment behaviors. These studies are all weakened by the lack of consistency in the measurement of these variables. Each research team appeared to have their own definitions of what constituted attachment behavior. No information was provided about breastfeeding initiation in either group.

To improve the methodological quality and reporting in similar clinical trials would be relatively easy. Investigators can provide more details in research reports regarding the method of random assignment, allocation concealment scheme, measures used to control for selection bias: context, timing, and modality of outcome measurements and means and standard deviations for the interval or ratio level outcome variables examined. However, control for provider and patient performance bias may continue to be problematic, because Institutional Review Boards require investigators to disclose the purpose of their study to potential participants so they can be informed when they consent to random assignment. Labor and delivery room staff often ask for group assignment of women before delivery so that they will know how to manage the infant immediately postbirth. Speaking more generally, recommendations by Thomson 1984 provide guidelines for well controlled clinical trials that remain important to this day.

Potential conflict of interest

Two of the reviewers have been active trialists in this area and have personal contact with many groups in this field including the International Network for Kangaroo Mother Care based in Trieste, Italy and Bogota, Colombia.

Acknowledgements

We thank Dr Busakorn Punthmatharith for her contributions during the earliest phases of the literature review, and Dr Mark W Lipsey for his assistance with the categorization of outcome measures for meta-analysis.

Characteristics of included studies

StudyAnisfeld 1983
MethodsQuasi-
randomized
controlled trial.
Group
assignment by day of week.
Participants59 healthy, full term infants and their mothers immediately postbirth.
Interventions1) Control group = briefly shown to the mothers, no contact until 3 hours postbirth, then contact at feedings every 4 hours. 2) Extra contact group = 45-60 minutes of SSC with the mother, then contact at feedings every 4 hours.
OutcomesObservation of maternal affectionate behaviors during feeding on day 2. Interview at 3 months old.
NotesStudy was done with low-middle income mothers in the USA, mixed parity.
Allocation concealmentC – Inadequate
StudyCarlsson 1978
MethodsOpen
randomized controlled trial.
Participants62 healthy, full term infants. The mothers were randomized into 1 of 3 groups before delivery.
Interventions1) Extended contact-new routine group = kept their naked infants for 1 hour immediately postbirth, mothers cared for infants. 2) Extended contact-old routine = kept their naked infants immediately postbirth for 1 hour, staff cared for infants. 3) Limited contact-old routine group = held their infants for 5 minutes immediately postbirth, staff cared for infants.
OutcomesObservation of maternal behavior (contact behavior and behavior not implying contact with baby) by videotape during breastfeeding on day 2 and 4 postbirth.
NotesStudy was done with middle income primipara in Sweden.
Allocation concealmentB – Unclear
StudyChristensson 1992
MethodsOpen randomized controlled trial.
Participants50 full term infants and their mothers randomized after the delivery.
Interventionsa) 80 minutes of SSC with the mother, b) 80 minutes in a cot.
OutcomesAxillary, thigh, and interscapular temperatures. Duration of crying. Blood glucose, base excess, respiratory rate, heart rate after 90 minutes.
NotesStudy was done in Madrid, Spain.
Allocation concealmentB – Unclear
StudyChristensson 1995
MethodsOpen randomized controlled trial.
Participants44 full term infants and their mothers immediately postbirth.
InterventionsGroup a) 76-85 min of SSC with the mother, b) infant in a cot for 76-85 min, c) infant in a cot for 35 min then skin-to-skin contact for 45 min.
OutcomesDuration of crying axillary temperature 90 minutes postbirth.
NotesStudy was done in Madrid, Spain.
Allocation concealmentB – Unclear
StudyCraig 1982
MethodsOpen randomized controlled trial (sealed envelopes, a table of random numbers by gender).
Participants60 healthy full term infants and their mothers.
Interventions1) Control group = mothers held their wrapped infants for 3 min then contact at feedings every 4 hours. 2) Early SSC group = infants were placed in SSC on their mother's chests for 54 min then contact at feedings every 4 hours.
Outcomes1) Neonatal perception inventory. 2) Interview of mother's experiences during pregnancy, delivery, 1st postpartum month. 3) Questions about infant behavior during a home visit at 1 month postbirth.
NotesStudy was done with low income primapara in the USA.
Allocation concealmentB – Unclear
StudyCurry 1982
MethodsOpen randomized controlled trial (sealed envelopes).
Participants20 healthy full term infants randomized during the first hour postbirth.
Interventions1) Control group = held their wrapped infants for 36 minutes during the first hour postbirth. 2) SSC group = held their infants in SSC for 35 minutes during the first hour postbirth. Both groups had 12 hours of rooming-in during the day.
Outcomes1) Seven maternal attachment behaviors (en face, kiss, hold, encompass, close contact and smile at) measured at 36 hours and 3 months postbirth during breastfeeding. 2) The Tennessee Self Concept measured at 2 months postbirth.
NotesStudy was done with well-educated, married, middle income, caucasian, breastfeeding primipara in the USA.
Allocation concealmentB – Unclear
StudyDe Chateau 1977
MethodsOpen randomized controlled trial
(open random numbers table).
Participants62 healthy full term infants and their mothers. Group 1 primiparous mothers and their infants n = 22. Group 2 primiparous mothers and their infants n = 20. Group 3 multiparous mothers and their infants n = 20.
InterventionsGroup 1: 15-20 minutes of SSC during the first hour postbirth. The infants were placed on the breast at 10 minutes postbirth and assisted by the midwives with breastfeeding. Groups 2 and 3 = routine care. The dressed babies were placed in a crib at the mother's bedside or in her bed at 10 minutes postbirth.
OutcomesObservation of mother's behavior during breastfeeding at 36 hours postbirth. Mother's and infant's behavior at 3 months during free play.
Breastfeeding at 3 months, 1 year postbirth. Mother's and infant's behavior during a physical exam and infant development at 12 months.
NotesStudy was done with middle income women in Sweden.
Allocation concealmentC – Inadequate
StudyFardig 1980
MethodsOpen randomized controlled trial
(blind drawing of 1 of 3 numbers with replacement).
Participants51 uncomplicated infants with gestation 38-42 weeks, birth weight of at least 2500 g, normal labour and delivery and normal Apgar score.
InterventionsGroup 1 infants were suctioned, dried under a radiant heater for 5 minutes and then placed naked on the mother's bare chest for 25 min. The infant's back was then covered with 2 cotton blankets. Group 2 infants were placed naked directly on the mother's chest for 28 min after the umbilical cord was cut. Group 3 infants were placed under a radiant warmer without being placed on the mother's chest.
OutcomesSkin temperature measured on the infant's left side every 3 minutes for 45 minutes. Rectal temperature at 21 and 45 minutes. Outcomes were the numbers of infants with skin or rectal temperature in the neutral range at 21 or 45 minutes.
NotesStudy was done in the USA.
Allocation concealmentB – Unclear
StudyHales 1977
MethodsOpen randomized controlled trial.
Participants60 healthy term infants randomized into 3 groups.
Interventions1) Control group = glance at babies immediately after delivery, swaddled infants brought to bedside at 12 hours postbirth, then daytime rooming-in.
2) Early contact group = 45 minutes of SSC immediately postbirth, daytime rooming-in. 3) Delayed contact group = 45 minutes of SSC at 12 hours postbirth, daytime rooming-in.
OutcomesObservation of maternal affectionate, proximity maintaining and caretaking behavior at 36 hours postbirth.
NotesStudy was done with low income, urban, breastfeeding primipara in Guatemala city.
Allocation concealmentB – Unclear
StudyMcClellan 1980
MethodsOpen randomized controlled trial (table of random numbers).
Participants40 healthy term infants born by repeat cesarean section (spinal anesthesia).
Interventions1) Control group = visual contact < 5 minutes, holding the swaddled infant for 10-20 minutes at the nursery during the first 12 hours postbirth, then rooming-in. 2) Early contact group = visual contact for 5 to 15 minutes, SSC for the first hour in the recovery room, then rooming-in.
Outcomes1) Neonatal perception inventory. 2) Postnatal research inventory. 3) Observation of maternal behavior.
All variables measured on postpartum day 1 or 2 and 28-32 days postbirth.
NotesStudy was done with middle income, multipara in the USA.
Allocation concealmentC – Inadequate
StudyShiau 1997
MethodsOpen randomized controlled trial
(computerized minimization technique).
Participants58 healthy full term infants and their mothers randomized into 1 of 2 groups 0-4 hours post vaginal or cesarean birth.
Interventions1) KC group = mothers began SSC at 4 hours postbirth and held their infants in SSC 8 hours daily for 3 days. Breastfeeding based on infant hunger cues during the day and every 4 hours at night. 2) Control group = began breastfeeding 24 hours postbirth. Mothers fed their infants every 4 hours in the nursery.
Outcomes1) Mean maternal state anxiety. 2) Mean score on 6 point breast engorgement scale. 3) Chest circumference. 4) Breastfeeding status day 3 and 28 postbirth. 5) Breast milk maturation. 6) Breastfeeding duration.
NotesStudy was done with married primipara and multipara in Taiwan. The researcher provided all nursing care to the SSC group during the day.
Allocation concealmentA – Adequate
StudySosa 1976a
MethodsOpen randomized controlled trial (random numbers in sealed envelopes).
Participants60 healthy full term infants and their mothers randomized immediately after delivery.
Interventions1) Experimental group = mothers held their infants in SSC for 45 minutes after the episiotomy repair. They were encouraged to breastfeed. 2) Control group = infants were separated from their mothers for 12 hours.
Outcomes1) Mean duration of breastfeeding. 2) Episodes of illness, growth and development, mortality.
NotesStudy was done with poor, urban primipara from the marginal area of Guatemala city.
Allocation concealmentB – Unclear
StudySosa 1976b
MethodsOpen randomized controlled trial (random numbers in sealed envelopes).
Participants68 healthy full term infants and their mothers randomized immediately after delivery.
Interventions1) Experimental group = mothers held their infants in SSC for 45 minutes after the episiotomy repair. They were encouraged to breastfeed. 2) Control group = infants were separated from their mothers for 12 hours.
Outcomes1) Mean duration of breastfeeding. 2) Episodes of illness, growth and development, mortality.
NotesStudy was done with poor, urban primipara from the marginal area of Guatemala city.
Allocation concealmentB – Unclear
StudySosa 1976c
MethodsOpen randomized controlled trial (random numbers in sealed envelopes).
Participants40 healthy full term infants and their mothers randomized immediately after delivery.
Interventions1) Experimental group = mothers held their infants in SSC for 45 minutes after the episiotomy repair. They were encouraged to breastfeed. 2) Control group = infants were separated from their mothers for 24 hours.
Outcomes1) Mean duration of breastfeeding. 2) Episodes of illness, growth and development, mortality.
NotesStudy was done with poor, urban primipara from the marginal area of Guatemala city.
Allocation concealmentB – Unclear
StudySvejda 1980
MethodsOpen randomized controlled trial.
Participants30 healthy full term infants and their mothers.
Interventions1) Control group = held their wrapped infants briefly (< 5 min) during transfer, then 30 min of contact at feedings every 4 hours. 2) Extra contact group = SSC for 15 minutes beginning 25 minutes postbirth, then the gowned mothers held their nude infants for 45 minutes in their rooms, 90 min of contact every 4 hours for feedings.
OutcomesVideotaped affectionale and proximity - maintaining behavior in interaction, affectionate and caretaking behavior during breastfeeding 36 hours postbirth.
NotesStudy was done with middle-income, primipara in the USA.
Allocation concealmentB – Unclear
StudySyfrett 1996
MethodsOpen randomized controlled trial - (computerized minimization technique).
Participants8 healthy preterm infants 34-36 weeks gestation, average for gestational age, Apgars 7 or more, and their mothers.
Interventions1) Control group = 24 min of SSC during the first hour postbirth before randomization to radient warmer for 3 hours, double wrapped in open bassinette for 3 hours then demand feeding and continuous rooming-in if stable. 2) KC group = 40 min of SSC during the first hour postbirth, transferred to nursery for admission procedures, then continuous SSC (mean 37 hours) and breastfeeding on demand.
OutcomesTemperature, temperature variability, breastfeedings/ day, bottle-feedings (ml/day), IV fluids (ml/day), weight loss (g/hr), birth-weight lost (%), number of heel sticks, length of stay (total days), breastfeeding duration.
NotesStudy was done in the USA. All nursing care in the KC group was done by the researchers.
Allocation concealmentA – Adequate
  1. a

    KC: kangaroo care
    Min: minutes
    SSC: skin-to-skin contact

StudyThomson 1979
MethodsOpen randomized controlled trial.
Participants34 healthy full term infants and their mothers.
Interventions1) Control group = held their wrapped infants briefly (< 5 min), subsequent contact at 12-24 hours postbirth, then contact every 4 hours for feedings during the day. 2) Early contact group = held infant in SSC for 15-20 min starting 15-30 min postbirth. Mothers were encouraged to breastfeed, subsequent contact at 12-24 hours postbirth, then contact every 4 hours for feedings during the day.
Outcomes1) Happy maternal reaction to birth. 2) Breastfeeding at hospital discharge. 3) Successful breastfeeding 2 months postbirth.
NotesStudy was done with married, primipara in Canada.
Allocation concealmentB – Unclear

Characteristics of excluded studies

StudyReason for exclusion
  1. a

    NICU: neonatal intensive care unit

Ali 1981No mention is made regarding whether the early maternal-infant contact is skin-to-skin.
Christensson 1998Infants in the control and intervention groups were hypothermic and admitted to the NICU before the study began.
Durand 1997Not a randomized trial, subjects self-selected into the experimental or control group based on their desire to breast or bottle feed.
Gomes-Pedro 1984The early contact in the intervention group was not skin-to-skin.
Grossman 1981A questionable quasi-randomization procedure is used - the experimental treatment and time are confounded. No mention is made regarding whether the early contact is skin-to-skin.
Johanson 1992The fullterm data were not reported separately; instead they were combined with preterm data in the analyses.
Johnson 1976No mention is made regarding whether the early maternal-infant contact is skin-to-skin.
Karlsson 1996Not a randomized trial; a descriptive study.
Klaus 1972The early contact in the intervention group was not skin-to-skin.
Lindenberg 1990No mention is made regarding whether the early maternal-infant contact is skin-to-skin.
Ottaviano 1979No mention is made regarding whether the early maternal-infant contact is skin-to-skin.
Salariya 1978No mention is made regarding whether the early maternal-infant contact is skin-to-skin.
Taylor 1979The early contact in the intervention group was not skin-to-skin.
Taylor 1985The early contact in the intervention groups was not skin-to-skin.
Taylor 1986Not a randomized trial, a descriptive study. The early contact in the intervention group was not skin-to-skin.

Characteristics of ongoing studies

StudyCarfoot 2001
Trial name or titleSuccessful breastfeeding: the effects of skin-to-skin contact.
Participants200 healthy pregnant women + 36 weeks gestation who intend to breastfeed.
InterventionsSkin-to-skin contact.
OutcomesSuccess of first breastfeed, prevalence of breastfeeding at 3 months.
Starting date01 January 2001
Contact informationMrs Susan Carfoot, Warrington Hospital NHS Trust, Maternity Dept., Lovely Lane, Washington, WA5 1QG.
Notes 

Analyses

Comparison 01. Skin-to-skin versus standard contact healthy infants
Outcome titleNo. of studiesNo. of participantsStatistical methodEffect size
01 Abdominal skin temp in neutral range after 21 minutes151Peto Odds Ratio 95% CI17.02 [3.49, 83.05]
02 Abdominal skin temp in neutral range after 45 minutes151Peto Odds Ratio 95% CI12.18 [2.04, 72.91]
03 Base excess at 90 minutes postbirth150Weighted Mean Difference (Fixed) 95% CI1.60 [0.13, 3.07]
04 Blood glucose mg/dl at 90 minutes postbirth150Weighted Mean Difference (Fixed) 95% CI11.07 [3.97, 18.17]
05 Respiratory rate at 90 minutes postbirth150Weighted Mean Difference (Fixed) 95% CI-5.50 [-10.56, -0.44]
06 Heart rate at 90 minutes postbirth150Weighted Mean Difference (Fixed) 95% CI-4.10 [-8.55, 0.35]
07 Interscapular temp 90 minutes postbirth150Weighted Mean Difference (Fixed) 95% CI0.50 [0.21, 0.79]
08 Axillary temperature 90 minutes postbirth279Weighted Mean Difference (Fixed) 95% CI0.43 [0.25, 0.60]
09 Mean axillary temperature18Weighted Mean Difference (Fixed) 95% CI0.30 [0.22, 0.38]
10 Not crying for > 1 minute during 90 minutes129Peto Odds Ratio 95% CI21.89 [5.19, 92.29]
11 Number babies not crying at 60 minutes postbirth136Odds Ratio (Fixed) 95% CI29.95 [1.57, 572.84]
12 Breastfeeding status day 3 postbirth156Weighted Mean Difference (Fixed) 95% CI1.60 [0.91, 2.29]
13 Breastfeeding at hospital discharge130Odds Ratio (Fixed) 95% CI3.21 [0.12, 85.20]
14 Breastfeeding status day 28 postbirth156Weighted Mean Difference (Fixed) 95% CI2.16 [1.19, 3.13]
15 Breastfeeding 1 month to 3 months postbirth8329Odds Ratio (Random) 95% CI2.15 [1.10, 4.22]
16 Breastfeeding 1 year postbirth262Odds Ratio (Fixed) 95% CI7.62 [0.89, 65.23]
17 Duration of breastfeeding in days6266Weighted Mean Difference (Fixed) 95% CI41.99 [13.97, 70.00]
18 Breast engorgement - pain 3 days postbirth156Weighted Mean Difference (Fixed) 95% CI-0.80 [-1.46, -0.14]
19 Breast engorgement - chest circumference day 3 postbirth156Weighted Mean Difference (Fixed) 95% CI-0.80 [-3.95, 2.35]
20 Breast milk maturation - early transitional milk on day 3156Odds Ratio (Fixed) 95% CI1.00 [0.35, 2.86]
21 Maternal state anxiety day 3 postbirth156Weighted Mean Difference (Fixed) 95% CI-5.00 [-9.00, 1.00]
22 Affectionate love/touch during breastfeeding 36-48 hours postbirth3119Standardised Mean Difference (Fixed) 95% CI0.73 [0.35, 1.11]
23 Holds infant during breastfeeding 36 hours/2nd day postbirth262Weighted Mean Difference (Fixed) 95% CI6.17 [2.70, 9.64]
24 Encompassing during breastfeeding 36 hours/2nd day postbirth262Weighted Mean Difference (Fixed) 95% CI3.83 [0.24, 7.43]
25 Maternal enface behavior during breastfeeding 36 hours postbirth140Weighted Mean Difference (Fixed) 95% CI3.80 [2.17, 5.43]
26 Maternal proximity-maintaining behavior during breastfeeding 36 hours postbirth140Weighted Mean Difference (Fixed) 95% CI9.50 [-0.25, 19.25]
27 Maternal caretaking behavior during breastfeeding 36 hours postbirth140Weighted Mean Difference (Fixed) 95% CI-0.20 [-4.01, 3.61]
28 Maternal contact behavior during breastfeeding day 2 postbirth142Weighted Mean Difference (Fixed) 95% CI47.04 [7.65, 86.43]
29 Maternal non-contact behavior during a breastfeeding day 2 postbirth142Weighted Mean Difference (Fixed) 95% CI-33.52 [-61.35, -5.69]
30 Maternal contact behavior during a breastfeeding day 4 postbirth142Weighted Mean Difference (Fixed) 95% CI59.23 [21.72, 96.74]
31 Maternal non-contact behavior during a breastfeeding day 4 postbirth142Weighted Mean Difference (Fixed) 95% CI-37.17 [-60.64, -13.70]
32 Maternal-infant behavior during a feeding postpartum day 1 or 2140Weighted Mean Difference (Fixed) 95% CI28.40 [9.25, 47.55]
33 Maternal-infant behavior during a feeding 28-32 days postbirth140Weighted Mean Difference (Fixed) 95% CI19.90 [10.87, 28.93]
34 Maternal scores on the Neonatal Perception Inventory day 1 or 2 postbirth140Weighted Mean Difference (Fixed) 95% CI1.90 [0.15, 3.65]
35 Maternal scores on the Neonatal Perception Inventory day 25 to 32 postbirth289Weighted Mean Difference (Fixed) 95% CI0.40 [-1.25, 2.04]
36 Mother kisses infant during a play observation 3 months postbirth260Weighted Mean Difference (Fixed) 95% CI0.23 [-0.16, 0.61]
37 Maternal enface behavior during a play observation 3 months postbirth260Standardised Mean Difference (Fixed) 95% CI1.75 [1.06, 2.43]
38 Mother holds infant positively during a physical exam at 1 year131Weighted Mean Difference (Fixed) 95% CI1.50 [0.51, 2.49]
39 Mother affectionate touching during a physical exam at 1 year131Weighted Mean Difference (Fixed) 95% CI0.85 [0.09, 1.61]
40 Maternal attachment behaviors during a feeding postpartum day 1-25211Standardised Mean Difference (Fixed) 95% CI0.76 [0.47, 1.04]
Analysis 01.01.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 01 Abdominal skin temp in neutral range after 21 minutes

Analysis 01.02.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 02 Abdominal skin temp in neutral range after 45 minutes

Analysis 01.03.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 03 Base excess at 90 minutes postbirth

Analysis 01.04.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 04 Blood glucose mg/dl at 90 minutes postbirth

Analysis 01.05.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 05 Respiratory rate at 90 minutes postbirth

Analysis 01.06.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 06 Heart rate at 90 minutes postbirth

Analysis 01.07.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 07 Interscapular temp 90 minutes postbirth

Analysis 01.08.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 08 Axillary temperature 90 minutes postbirth

Analysis 01.09.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 09 Mean axillary temperature

Analysis 01.10.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 10 Not crying for > 1 minute during 90 minutes

Analysis 01.11.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 11 Number babies not crying at 60 minutes postbirth

Analysis 01.12.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 12 Breastfeeding status day 3 postbirth

Analysis 01.13.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 13 Breastfeeding at hospital discharge

Analysis 01.14.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 14 Breastfeeding status day 28 postbirth

Analysis 01.15.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 15 Breastfeeding 1 month to 3 months postbirth

Analysis 01.16.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 16 Breastfeeding 1 year postbirth

Analysis 01.17.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 17 Duration of breastfeeding in days

Analysis 01.18.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 18 Breast engorgement - pain 3 days postbirth

Analysis 01.19.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 19 Breast engorgement - chest circumference day 3 postbirth

Analysis 01.20.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 20 Breast milk maturation - early transitional milk on day 3

Analysis 01.21.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 21 Maternal state anxiety day 3 postbirth

Analysis 01.22.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 22 Affectionate love/touch during breastfeeding 36-48 hours postbirth

Analysis 01.23.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 23 Holds infant during breastfeeding 36 hours/2nd day postbirth

Analysis 01.24.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 24 Encompassing during breastfeeding 36 hours/2nd day postbirth

Analysis 01.25.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 25 Maternal enface behavior during breastfeeding 36 hours postbirth

Analysis 01.26.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 26 Maternal proximity-maintaining behavior during breastfeeding 36 hours postbirth

Analysis 01.27.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 27 Maternal caretaking behavior during breastfeeding 36 hours postbirth

Analysis 01.28.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 28 Maternal contact behavior during breastfeeding day 2 postbirth

Analysis 01.29.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 29 Maternal non-contact behavior during a breastfeeding day 2 postbirth

Analysis 01.30.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 30 Maternal contact behavior during a breastfeeding day 4 postbirth

Analysis 01.31.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 31 Maternal non-contact behavior during a breastfeeding day 4 postbirth

Analysis 01.32.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 32 Maternal-infant behavior during a feeding postpartum day 1 or 2

Analysis 01.33.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 33 Maternal-infant behavior during a feeding 28-32 days postbirth

Analysis 01.34.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 34 Maternal scores on the Neonatal Perception Inventory day 1 or 2 postbirth

Analysis 01.35.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 35 Maternal scores on the Neonatal Perception Inventory day 25 to 32 postbirth

Analysis 01.36.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 36 Mother kisses infant during a play observation 3 months postbirth

Analysis 01.37.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 37 Maternal enface behavior during a play observation 3 months postbirth

Analysis 01.38.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 38 Mother holds infant positively during a physical exam at 1 year

Analysis 01.39.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 39 Mother affectionate touching during a physical exam at 1 year

Analysis 01.40.

Comparison 01 Skin-to-skin versus standard contact healthy infants, Outcome 40 Maternal attachment behaviors during a feeding postpartum day 1-2

Sources of support

External sources of support

  • NINR, NIH, R01 NR02444 to GCA USA

Internal sources of support

  • Edward J and Louise Mellen Endowment to GCA USA

Ancillary