The main purpose of this review was to analyse the impact of the intervention, extra breastfeeding support, compared with usual maternity care, with the purpose of facilitating continued breastfeeding. We included studies if the intervention occurred in the postnatal period alone or if it also included an antenatal component. We excluded interventions taking place in the antenatal period alone, as well as interventions described as solely educational in nature.
Primary outcomes were recorded for stopping any or exclusive breastfeeding before four to six weeks and at the last assessment up to six months Other outcomes of interest were stopping breastfeeding at other time points, measures of neonatal and infant morbidity (where available) and measures of maternal satisfaction with care or feeding method.
Description of included studies (n = 52)
Fifty-two included studies contribute data to this update of the review. The total number of mother-infant pairs in these studies is 56,451 (this total was 29,385 in the previous version of this review Britton 2007). The 52 studies were published/conducted between 1979 and 2011 and show increases over time both in number of studies (five studies are dated earlier than 1990, 10 are dated 1990 to 1999 and 37 are dated 2000 to 2011) and range of country settings (the seven studies with dates earlier than 1994 were all undertaken in high-income countries, and the four studies from low/low-middle income countries were published in 2000 or later). The data in this review come from participants living in 21 countries. Using the World Bank classification of countries by income (http://data.worldbank.org/about/country-classifications/country-and-lending-groups, accessed 25 Oct 2011):
two studies with 2285 participants (4% of the total number of participants) were conducted in low-income countries (Bangladesh, Haider 2000; Burkina Faso and Uganda, Tylleskar 2011a; Tylleskar 2011b);
two studies with 1717 participants (3%) were conducted in low-middle-income countries (India, Bhandari 2003; Syria, Bashour 2008);
12 studies with 21,649 participants (38%) were conducted in upper-middle-income countries (Belarus, Kramer 2001; Brazil, Albernaz 2003; Barros 1994; Coutinho 2005; de Oliveira 2006; Leite 2005; Santiago 2003; and Vitolo 2005; Iran, Froozani 1999; Mexico, Morrow 1999; Turkey, Aksu 2011 and South Africa, Tylleskar 2011c1);
37 studies with 30,800 participants (55%) were conducted in high-income countries (Australia, McDonald 2010 and Quinlivan 2003; Canada, Dennis 2002; Gagnon 2002; Lynch 1986; Mongeon 1995; Porteous 2000; and McQueen 2011; Denmark, Kronborg 2007; France, Labarere 2005; Italy, Di Napoli 2004; Netherlands, Kools 2005; Singapore, Su 2007; Sweden, Sjolin 1979 and Ekstrom 2006; UK, Graffy 2004; Hoddinott 2009; Jones 1985; Jenner 1988; Morrell 2000; Muirhead 2006; Sinclair 2007; and Winterburn 2003; US, Brent 1995; Bonuck 2005; Bunik 2007; Chapman 2004; Di Meglio 2010; Frank 1987; Grossman 1990; Hopkinson 2009; Petrova 2009; Pugh 1998; Pugh 2002; Pugh 2007; Serafino-Cross 1992; and Wrenn 1997).
1 Note: The study by Tylleskar et al (Tylleskar 2011a; Tylleskar 2011b; Tylleskar 2011c) was undertaken in three countries, two in the low-income and one in the upper middle income World Bank category. In this review, we have entered data into the analyses separately for each country.
Methods used in trials
The 52 studies include 44 individually-randomised trials and eight cluster-randomised trials.
Participants and setting
Socio-economic and health status
Participants were women from the general healthy population of their countries. However, 19 of the 52 studies were undertaken with women from low-income groups within their country. These 19 studies include 12 of the 14 US studies, with two other studies from high-income countries (Jones 1985; Quinlivan 2003), three of the studies from Brazil (Barros 1994; Coutinho 2005; Vitolo 2005), and the two studies from low-income countries. In one of these (Haider 2000, Bangladesh), participants were mainly of lower-middle and low socio-economic status. In the other (Tylleskar 2011a; Tylleskar 2011b; Tylleskar 2011c), participants came from three countries in sub-Saharan Africa, with those in one country (Uganda) from low-income groups within that country. With regard to health of the general population of countries, this author notes local HIV prevalence rates of 10% to 34% in the South Africa study sites; during recruitment, women who had not been HIV tested were encouraged to visit the antenatal clinic, and those who disclosed HIV positive status were recruited into another study.
Background rates of breastfeeding initiation/“ever breastfed”
Among the 52 studies, World Bank country income group shows an inverse relationship with background rates of breastfeeding initiation ("ever breastfed"). All the studies with intermediate (60% to < 80%, n = 18) or low (< 60%, n = 11) background rates of breastfeeding initiation were undertaken in high-income countries. Nine of the 11 studies with low background rates recruited women from low-income groups in the US (Brent 1995; Bonuck 2005; Bunik 2007; Chapman 2004; Di Meglio 2010; Frank 1987; Grossman 1990; Pugh 2002; Serafino-Cross 1992); the remaining two (UK) studies were from areas of Scotland with lower breastfeeding initiation rates than the Scottish average (Hoddinott 2009; Muirhead 2006). All the country income groups are represented among the 24 studies with high (≥ 80%) rates, however the four studies from low-/low-middle-income countries all have very high rates (≥ 95% ever breastfed). Where background rates of “ever breastfed” were not reported, we have used rates published in The WHO Global Data Bank on Infant and Young Child Feeding http://www.who.int/nutrition/databases/infantfeeding/countries/en/index.html (and for the two studies from Scotland (Hoddinott 2009; Muirhead 2006), we used http://www.isdscotlandarchive.scot.nhs.uk/isd/1914.html, both accessed November 2011).
Hospital (Baby Friendly) and community settings
Twenty-two of the 52 studies were carried out both on hospital postnatal wards and in community settings (these include hospital and community clinics). Five of the 22 hospital-based studies were set in hospitals with Baby Friendly accreditation (Aksu 2011; Chapman 2004; Coutinho 2005; de Oliveira 2006; Sinclair 2007). Thirty studies were conducted in community settings only. In one of these (Kronborg 2007), the five hospitals serving the area from which the study participants were recruited had all adopted the standards of the Baby Friendly Hospital Initiative, and three of them were certified as Baby Friendly. In another (Hoddinott 2009) the clusters were seven intervention group localities paired with seven control group localities. In the intervention group, the number of localities in which the hospital where most women gave birth had the Baby Friendly award was three before the intervention and four after the intervention. In the control group, the corresponding numbers were four localities before and six after the intervention.
Level of the intervention
In 45/52 studies, women received the intervention. In six studies (three cluster-randomised trials; Bhandari 2003; Ekstrom 2006; and Kramer 2001, and three individually-randomised trials; Labarere 2005; Santiago 2003; Sinclair 2007), the intervention was additional training in breastfeeding support for staff. One cluster-randomised trial (Hoddinott 2009) evaluated a policy for providing breastfeeding groups.
Breastfeeding support: proactive/indirect
In 41/45 of the studies where women received the intervention and five of the six studies of staff training, breastfeeding support was delivered directly to women. In five other studies (Graffy 2004; Hoddinott 2009; Labarere 2005; Morrell 2000; Winterburn 2003), breastfeeding support was not proactively offered; women were encouraged to access it, but breastfeeding support was not delivered directly to women as part of these interventions. One study (Kools 2005) evaluated a multi-faceted intervention of which breastfeeding support delivered directly to women was one component.
In 48/52 studies there was individual, one-to-one contact between the breastfeeding supporter and the breastfeeding mother. One study (Hoddinott 2009), offered group support, one (Ekstrom 2006) offered both individual and group support, and in two studies this aspect of support was unclear (Kools 2005; Kramer 2001).
Breastfeeding support from professional/ lay supporters
In the previous edition of this review, the people providing breastfeeding support were categorised as 'professional', 'lay and professional' or 'lay'. Using those categories, the 52 studies in this update comprise 30 studies of professional support, nine of lay and professional support and 13 of lay support. In view of the growing body of work evaluating breastfeeding peer support, we have distinguished between this and other kinds of lay support, following the definition by Dennis 2002: “Peer support is provided by lay individuals who are not part of the client’s own embedded network, who possess experiential knowledge of the targeted behaviour (i.e. successful breastfeeding skills) and similar qualities (i.e. age, socioeconomic status, ethnicity, residency etc.,) in order to aid the client during a time of actual or potential stress (i.e. the initiation and continuation of breastfeeding”.
In 30/52 studies a variety of medical, nursing and allied professionals (for example, nutritionists, lactation consultants and researchers) provided the breastfeeding support (Albernaz 2003; Bunik 2007; Bashour 2008; Bonuck 2005; Brent 1995; de Oliveira 2006; Di Napoli 2004; Ekstrom 2006; Frank 1987; Froozani 1999; Gagnon 2002; Jones 1985; Kramer 2001; Kronborg 2007; Lynch 1986; McDonald 2010; McQueen 2011; Petrova 2009; Porteous 2000; Pugh 1998; Quinlivan 2003; Santiago 2003; Serafino-Cross 1992; Sinclair 2007; Sjolin 1979; Su 2007; Vitolo 2005; Wrenn 1997).
Professional and lay
Professionals provided breastfeeding support with other people in a further nine studies; para-professionals (Kools 2005; Morrell 2000), peer supporters (Bhandari 2003; Hopkinson 2009; Pugh 2002; Pugh 2007), and lay people (employees who had to be mothers in Barros 1994; someone chosen by the mother in Winterburn 2003; and a group of mothers in Hoddinott 2009).
Lay people provided breastfeeding support in 13 studies. In eight of these, the lay people were peer supporters (Chapman 2004; Dennis 2002; Di Meglio 2010; Haider 2000; Leite 2005; Morrow 1999; Muirhead 2006; Tylleskar 2011a; Tylleskar 2011b; Tylleskar 2011c). The other five studies (Aksu 2011; Coutinho 2005; Graffy 2004; Jenner 1988; Mongeon 1995) did not report that the lay supporters met the criteria (Dennis 2002) for us to classify them as peer supporters.
Training in breastfeeding support
Overall, 36/52 studies report that the people providing breastfeeding support had additional training to provide breastfeeding support (21/30 professional, 3/9 professional and lay and 12/13 peer/lay). Sixteen of the 21 studies where professionals had additional training give details of the training. In eight studies, the training was specific to the study (Bashour 2008; de Oliveira 2006; Ekstrom 2006; Labarere 2005; McDonald 2010; Santiago 2003; Sinclair 2007; Vitolo 2005) and lasted, where reported, five to 16 hours. In five of the remaining eight studies professionals had WHO/Unicef training for 18 hours (Di Napoli 2004; Kramer 2001; Kronborg 2007) or 40 hours (Albernaz 2003; Froozani 1999) and in three studies the professionals were International Board Certified Lactation Consultants (IBCLC) (Brent 1995; Petrova 2009; Pugh 1998).
In one of the studies of support from professionals and paraprofessionals, the professionals were lactation consultants (Kools 2005) and in the other they were midwives not stated to have had extra training in breastfeeding support (Morrell 2000); in both these studies the para-professionals were trained to refer women with breastfeeding problems to the professionals. Two of the four studies of support from professionals and peers reported training; in Bhandari 2003 peer supporters received WHO-based training, and in Hopkinson 2009 the professionals were IBCLCs and the peer supporters had three days training in lactation management, 20 hours training in peer counselling and at least one year’s work experience. One of the three studies study of professional and lay support states lay supporters received breastfeeding support training (Barros 1994).
All eight studies of peer support (alone) reported peer supporters were trained. The training was WHO 20 hours (Leite 2005), 40 hours (Haider 2000) or one week (Tylleskar 2011); La Leche League (LLL) 30 hours (Chapman 2004), 20 hours (Di Meglio 2010) and length not specified (Morrow 1999). Two studies reported the length but not the type of training; 2.5 hours (Dennis 2002) and more than two days (Muirhead 2006). Three of the five studies of lay support (alone) reported breastfeeding training; WHO 18 hours plus five days (Coutinho 2005), WHO 18 hours (Aksu 2011) and National Childbirth Trust training (Graffy 2004).
Mode of support (face-to-face and/or by telephone)
Twenty-seven of the 52 studies offered telephone support and all but one of these (Albernaz 2003, Brazil) were undertaken in countries classified High Income by the World Bank. Three studies (Dennis 2002; Bunik 2007; Di Meglio 2010) offered breastfeeding support only by telephone. Twenty-four offered both face-to-face and telephone support, with telephone support either predominant (e.g. Muirhead 2006; Petrova 2009) or as backup (e.g. Chapman 2004). In some studies (e.g. Kools 2005; Pugh 1998), telephone contact with the breastfeeding support specialist came after the women had been visited by someone else. Across the 27 studies examining telephone support, details of whether or not the telephone support was proactively offered by the peer or professional supporter were not consistently reported. Twenty-four studies offered only face-to-face support. In the one remaining study (Winterburn 2003), the support was not proactive and the mode of support was not specified.
Support with an antenatal component and intention to breastfeed
The outcomes of interventions intended to promote longer duration of breastfeeding could be expected to differ according to whether women were recruited before or after they started to breastfeed. Two-thirds of the studies (34/52) included postnatal women at or after initiation of breastfeeding. In the one study of breastfeeding in groups (Hoddinott 2009), pregnant women and breastfeeding mothers could be invited to attend groups. The remaining 17 studies recruited women before the birth, not all of whom went on to initiate breastfeeding. Six of the 17 studies (Kramer 2001, Belarus; Jenner 1988 and Winterburn 2003, UK; Serafino-Cross 1992, US; Mongeon 1995, Canada; Tylleskar 2011a; Tylleskar 2011b; Tylleskar 2011c, Burkina Faso, Uganda and South Africa) included only women who intended to breastfeed. In the study by Tylleskar 2011, this inclusion criterion was related to HIV/AIDS prevention and management in the country and study populations. Eleven studies that recruited before the birth did not specify that participants had to intend to breastfeed.
Intensity of the intervention
Forty-five of the 52 studies reported the intensity of the intervention in terms of the number of postnatal contacts the mother could have for breastfeeding support. Sixteen studies specified three or fewer contacts, 16 four to eight contacts, and the remaining 13 studies specified nine or more contacts. We have performed a subgroup analysis and results are described in the text.
Duration of the intervention and duration of data collection
The length of time between the end of an intervention and collection of outcome data could be a factor in effectiveness of the intervention. Among the 52 studies, duration of the intervention ranged from three days to one year and the last data collection point for breastfeeding outcomes ranged from two weeks to 18 months (note the analyses in this review only include data where follow-up was at least 75%). For 46/52 studies it was possible to calculate the length of time between the end of the intervention and the end of data collection. In 21 studies the intervention and data collection ended at the same time (at one year in three studies; six months in seven studies; five months in one study; four months in four studies; three months in five studies and at four weeks in one study, Porteous 2000). In the remaining 25 studies the time interval between the end of the intervention and the end of data collection ranged from 1.5 weeks (Gagnon 2002) to 17.9 months (Aksu 2011); in these two studies the intervention ended at four and three days respectively.
Control group care
Five of the 52 studies were undertaken in hospital settings with Baby Friendly accreditation (Aksu 2011; Chapman 2004; Coutinho 2005; de Oliveira 2006; Sinclair 2007). These study interventions were additional to care that met Baby Friendly standards and were received by everyone at the hospital including all the study participants in the intervention and control groups. In two community-based cluster-randomised trials (Hoddinott 2009; Kronborg 2007), most of the maternity hospitals in which the participants had given birth had Baby Friendly accreditation. In 20 studies control group care was not specified (n = 7) or stated to be standard care but not described (n = 13). In half the studies (27/52) there was some description of control group care (see Characteristics of included studies). Standard postnatal care varies both between and within countries. Care may have differed within the study period and may also have differed from that which is offered at the present time.
Level of data collection
In 45/52 studies data outcome data were collected from the women who had received the intervention. In the other seven studies, the relationship between the recipients of the intervention and the source of the outcome data varied. In the three individually-randomised trials of staff training (Labarere 2005; Santiago 2003; Sinclair 2007), outcome data came from all the women randomised to receive, or not to receive, a support intervention from trained staff. In one of the three cluster-randomised trials of staff training (Ekstrom 2006), data came from mothers of singleton term healthy infants at centres where staff had been randomised, or not randomised, to receive training. In another (Bhandari 2003) trained staff visited all families in the intervention villages and outcome data were collected from all infants in the intervention and control villages, and in the third (Kramer 2001), staff in all intervention sites were trained and data were collected from mothers who intended to breastfeed in the intervention and control sites. In the cluster-randomised trial that evaluated a policy for providing breastfeeding groups (Hoddinott 2009), the policy intervention was made at locality level. Pregnant or postnatal women could be invited to groups in intervention clusters; however, only 1310 pregnant or breastfeeding women out of more than 9000 births in the intervention localities attended any group.
Duration of any and/or exclusive breastfeeding
The breastfeeding outcomes reported reflect World Bank country income group of the countries where the 52 studies were undertaken. Most studies (29/52) report the effect of the intervention on rates of both any and exclusive breastfeeding. However, all 14 studies that only report any breastfeeding were undertaken in high-income countries, and the nine studies that only report exclusive breastfeeding include all four from low-/lower-middle-income countries. Some studies newly included in this review report details about data collection that make it clear duration of exclusive breastfeeding at specific time points was not necessarily measured from birth (Tylleskar 2011a; Tylleskar 2011b; Tylleskar 2011c; Vitolo 2005); most studies do not report this level of detail.
A few studies reported various infant morbidity and maternal satisfaction with feeding and care outcomes by intervention group, as follows: infant morbidity in 11 studies (Bashour 2008; Bhandari 2003; Bunik 2007; Frank 1987; Froozani 1999; Kramer 2001; Morrow 1999; Petrova 2009; Pugh 2002; Quinlivan 2003; Tylleskar 2011a; Tylleskar 2011b; Tylleskar 2011c); maternal satisfaction with feeding in 11 studies (Bashour 2008; de Oliveira 2006; Dennis 2002; Hoddinott 2009; Hopkinson 2009; Kronborg 2007; Labarere 2005; McDonald 2010; McQueen 2011; Petrova 2009; Pugh 1998) and maternal satisfaction with care in six studies (Bashour 2008; Ekstrom 2006; Graffy 2004; Jones 1985; Kools 2005; Morrow 1999).