What’s new in the other journals?
These snippets are extracts from a monthly service called the Journal Article Summary Service. It is a service that summarises all that is new in obstetrics and gynaecology over the preceding month. If you would like to know the details of how to subscribe, please email the editor Athol Kent at firstname.lastname@example.org or visit the website www.jassonline.com.
Caesarean section rates and dangers
The challenge of climbing caesarean section rates will simply not go away. The profession has to deal with this escalating worldwide phenomenon, and two articles are summarised which are particularly revealing.
The first comes from Latin America. Villar et al. reviewed 100 000 deliveries from selected sites in eight countries and related the caesarean section rates to outcomes, both maternal and neonatal (Lancet 2006;367:1819–29). The countries involved have the highest caesarean section rates in the world but fall neither into the highest or lowest socio-economic categories nor do they have the highest expenditure on health per capita. If they represent the way of the future, then their maternal and neonatal outcomes are of considerable interest to countries whose statistics are heading in a similar direction.
The results are disturbing. The overall caesarean section rate was 33%, with peaks of more than 50% noted in some private institutions. As rates rose, so did maternal morbidity and mortality. So did perinatal mortality rates, plus the number of infants admitted to intensive care units for a week or longer. These data were adjusted for risk factors and prematurity, so there is little doubt that the mode of delivery was the crucial factor.
The rates were pretty uniform across the countries studied in South and Central America. Elective caesarean section was a frequently stated reason for surgery in private hospitals. The largest single indication was, however, a previous caesarean section. The raised maternal morbidity findings were substantiated by the greater use of nonprophylactic antibiotics and longer postpartum hospital stays. The poorer neonatal outcomes were contrary to findings from developed countries and, surprisingly, held true for elective as well as intrapartum caesarean sections. The authors state that ‘Our results show how a medical intervention or treatment that is effective when applied to sick individuals in emergency situations can do more harm than good when applied to healthy populations’. They suggest that institutions with high caesarean section rates are causing iatrogenic harm.
Victora and Barros (Lancet 2006;367:1796–7) discuss some Latin factors to explain these high rates, such as private doctors knowing that the most efficient use of their time—both business and leisure—is to cut rather than spend hours in hospital waiting for a vaginal delivery. They accept that consumer demand fuels the fire and these, in turn, are driven by social pressures such as celebrity elective caesarean sections and poor intrapartum monitoring. Private hospitals are unlikely to implement policies that reduce theatre, anaesthetic and drug spending.
The second article by Silver et al. from USA looks at the maternal morbidity associated with repeat caesarean sections (Obstet Gynecol 2006;107:1226–32). They studied more than 30 000 women undergoing an elective caesarean section in 19 academic centres to see if increasing numbers of caesarean sections increased the morbidity in any given woman. There were sufficient numbers to analyse women having their first to sixth (or more) operation.
The following problems increased with increasing caesarean sections in a ‘dose-related’ fashion—placenta accreta, cystotomy, bowel or ureteral injury, ileus, postoperative ventilation, intensive care admissions, hysterectomy, blood transfusions, duration of operation and postoperative hospital stay. Specifically, in women with placenta praevia, the risk for placenta accreta was 3, 11, 40, 61 and 67% for first, second, third, fourth and fifth or more repeat caesarean sections.
The overall outcomes were good, despite the complications, but the authors point out that the centres studied were tertiary institutions with special facilities and experienced staff, so generalisability to less sophisticated situations needs to be cautious. These data have important implications for women and their doctors deciding to carry out her first caesarean section, irrespective of her parity, but especially when contemplating her first delivery ‘abdominally on demand’.
Obesity, death and breast cancer
The American journals are obsessed with obesity. And rightly so.
In the last quarter of the last century, the prevalence of obesity in the USA doubled, while extreme obesity has quadrupled. What this means to women in terms of their mortality is now becoming clear. The Women’s Health Initiative observational study looked at women in their 50s, 60s and 70s who were, or were not, taking hormonal replacement therapy and followed them diligently for at least 7 years.
McTigue et al. (JAMA 2006;296:79–86) now report on the mortality rates in more than 90 000 women of varying categories of body mass index (BMI) from normal to extremely obese.
The authors conclude that an increasing BMI has a progressive effect, with the greater the excess weight, the greater the risk of dying, especially from coronary heart disease.
Weight gain in women is not only a threat to their longevity but also increases their chances of developing breast cancer (Eliassen et al. JAMA 2006;296:193–201). The Nurses’ Health Study continues to provide data from 87 000 participants who entered the survey 30 years ago, and now, weight increases pre and postmenopausally can be related to a woman’s chance of developing breast cancer.
Those who gained 25 kg since the age of 18 years had a relative risk of 1.45 compared with those maintaining their weight. Those who gained 10 kg since menopause had a relative risk of 1.18. The effects are probably mediated through adipose tissue being the main source of oestrogen production after the menopause. Women with higher BMIs have a two-fold increase in circulating oestrogens compared with normal weight women, with raised bioavailability from more endogenous oestrogens and lower sex-hormone-binding globulin levels. Weight reduction in women decreases oestrogen production as well as raising globulin levels, resulting in a protective effect against breast cancer.
The bottom line is weight gain since the age of 18 years increases the risk of postmenopausal breast cancer. This is most marked in women who do not take hormone replacement therapy. The corollary is that women who lose weight, even after the menopause, reduce their risk of breast cancer.
Female genital mutilation
The barbaric practice of female genital mutilation (FGM) is estimated to have been carried out on 100 million women worldwide. It is the partial or total removal of the external genitalia for cultural reasons and is classified into three categories:
- • FGM I—excision of the prepuce, with or without excision of part or all the clitoris
- • FGM II—excision of the clitoris, with partial or total removal of the labia minora
- • FGM III—excision of part or all of the external genitalia and stitching or narrowing of the vaginal opening (infibulation).
Attempts to eliminate the practice have to cover a wide spectrum of beliefs and customs. To date, only anecdotal evidence has been available about the effect of FGM on obstetric outcomes, so medical epidemiology has not had a large part to play in the moves to eradicate FGM. Now a World Health Organization study has been published, which clearly relates FGM to adverse obstetric outcomes (Lancet 2006;367:1835–41) in six African countries.
Compared with women without FGM, the risk of caesarean section, postpartum haemorrhage, episiotomy, extended maternal hospital stay, infant resuscitation and stillbirth or early neonatal death are all increased, and the increase was greater with more extensive FGM. It was a large study (nearly 30 000 women) gathering wide-ranging data about socio-economic status, urban or rural residence, religious affiliation and education. The hospitals surveyed were situated in regions where the practice is performed on three-quarters of the population.
These regions have a background of high maternal and neonatal adverse outcomes so the abandonment of FGM could significantly contribute to neonatal and perinatal wellbeing. These data will add weight to the fight against this appalling human rights violation by education in an area devoid of reason (Eke and Nkanginieme Lancet 2006;367:1799–800).
When to clamp the cord
The active management of the third stage of labour has saved countless lives. It is routine care in most obstetric units to prevent postpartum haemorrhage but there is one component—that of early cord clamping—that deserves scrutiny. In nature, most of the placental blood is transferred to the infant in the first minute after birth and the cord stops pulsating after 2 minutes. The question arises whether early cord clamping prevents this ‘auto transfusion’ and deprives the infant of iron he or she would otherwise receive.
Chaparro et al. from Mexico City (Lancet 2006;362:1997–2004) looked at the haematology after 6 months of those with early clamping and those where clamping was delayed for 2 minutes. Infants with delayed clamping had significantly higher mean corpuscular volumes, ferritin and iron stores. An increase of 35 mg of iron stores was apparent which was most valuable in infants born to mothers with low ferritin or breastfed babies who did not receive iron supplement or low birthweight infants.
Mercer and Erickson-Owens (Lancet 2006;362:1956–7) confirm the historical basis of early clamping without scientific proof. They discount over-transfusion, polycythaemia and potential negative results of uterotonic drugs being used in conjunction with delayed clamping. It is suggested that keeping the baby at the same level as the mother, giving oxytocin and delaying cord clamping for 2 minutes (or until pulsations cease) is good practice, especially in developing countries.
With all the exhortations to ‘store cord blood for future stem cell use’, there is the impression that cord blood is medical waste. This is simply untrue, and there is no need to collect and store cord blood unless there is a known family need. The American Academy of Pediatrics agrees, and with the increasing commercial offers to store stem cells ‘for your baby’s future’, it may be well to heed this advice.
Life after death
There are major ethical dilemmas in declaring a pregnant woman ‘brain dead’. Isolated cases have been reported where ventilation or other means have been used to support a woman who would otherwise be declared dead until the fetus is considered viable.
Another report has now been added to the literature making 11 cases in all. An Italian woman was kept alive artificially from 18 to 29 weeks before a fall in blood pressure precipitated an emergency delivery by caesarean section and a healthy girl was born (BMJ 2006;332:1468).
Sex at term
Women legitimately enquire whether sexual intercourse can be detrimental during pregnancy. If they do not ask, it is good practice to discuss it anyway. There is little firm evidence that sex impacts negatively on pregnancy, and anecdotally, it is believed that intercourse around term may ripen the cervix or hasten labour.
Schaffir (Obstet Gynecol 2006;107:1310–14) surveyed low-risk women about sexual activity between 38–42 weeks of gestation and related this to Bishop score findings and the onset of labour. There was no significant relationship between coitus and cervical changes or uterine contractions leading to labour.
No doubt other studies will find contradictory results, but it is hardly an area where randomised trials will settle the issue. What can be concluded is that sex at term does not have adverse outcomes.