Caesarean section delivery, an increasingly popular option

The number of women having babies born by caesarean section is growing exponentially in many parts of the world, if a UK audit released in October by the Royal College of Obstetricians and Gynaecologists is anything to go by. The audit reports that 22% of British babies are now being born by this method, vs 4% 30 years ago. In parts of the country, rates of more than 24% are not uncommon.

Examples abound of other countries where caesarean section is enjoying unprecedented popularity. The US rate is about the same as that of the UK. In Chile, 40% of births are by this route, a record for Latin America. And in Brazil's public hospitals, up to 80% of pregnant women reportedly give birth by caesarean section. In sub-Saharan Africa, rates of around 22% and more are not uncommon.

Clearly, in both industrialized and developing countries WHO's recommended rate of 15% doesn't carry much weight. Dr José Villar, WHO's coordinator for family and community health, says this level was established by about 1985 and represents "a reasonable figure set in accordance with expert opinion and based on what was known at the time".

Why the growing popularity of caesarean delivery? Convenience may be one reason: with caesarean section, a woman — and her obstetrician — can choose the time of childbirth. Safety could be another.

Dr Alexandre Dumont of Senegal's health ministry notes in a review of caesarean section use in Africa (published in the 20 October 2001 issue of The Lancet), that three- quarters of caesarean deliveries in sub- Saharan hospitals are nearly all carried out for one or more of six reasons — protracted labour, previous caesarean section, difficult fetal presentation, premature detachment of the placenta (abruptio placentae), placental presentation (placenta praevia), and eclampsia. Caesarean section, he says, is "one of the most effective means of reducing maternal mortality".

It also seems to be relatively safe, compared with vaginal delivery. A randomized 26-country trial in 2088 breech presentation pregnancies, reported in the 27 March 1999 issue of The Lancet by Canada's term breech trial collaborative group, found significantly lower perinatal and neonatal mortality rates and lower severe neonatal morbidity rates for the pregnancies where caesarean delivery was chosen than for the group of women who delivered by the vaginal route. In the same issue of The Lancet, the European mode of delivery collaboration, a consortium of 43 obstetric clinics in six European countries, reported evidence from a randomized clinical trial involving 436 women that caesarean section significantly lowers the risk of mother-to-child transmission of HIV infection without increasing the risk of complications to the mother.

Villar and his colleagues believe that there is "an unfortunate imbalance": some high-risk populations with very low caesarean section rates should increase the availability of caesarean section, where indicated by obstetrical complications. Other populations, with very high rates, might introduce ways of discouraging unnecessary recourse to caesarean section. But just what "excessive" is and what the right rate should be await definition. "We are collaborating with all interested parties around the world," says Villar, "in order to identify what a realistic and safe range would be."

Laszlo Dosa, Jupiter, Florida, USA

World Health Organization Genebra - Genebra - Switzerland