Multicentre study on risks and benefits of caesarean delivery, Latin America.
A multicentre, prospective study assessing the risks and benefits
associated with caesarean delivery, compared with vaginal delivery,
prompted a large number of rapid responses on the BMJ website. The
study, part of the 2005 WHO global survey on maternal and perinatal
health, examined data from nearly 97,000 deliveries during a three-month
period in 120 facilities from 24 areas in eight Latin American countries
(all randomly-selected). Women undergoing caesarean deliveries, either
intrapartum or elective, had double the risk for severe maternal
morbidity and mortality, and up to five times the risk of post-partum
infection compared with vaginal delivery. Although caesarean section has
a slightly reduced risk of fetal death at birth, with cephalic
presentation it is significantly associated with an increase in severe
neonatal morbidity and mortality, independent of fetal distress and
gestational age. With breech presentation, caesarean delivery
substantially reduces risks to the baby. Any net benefit from the
liberal use of caesarean delivery remains to be demonstrated, with the
exception of fewer severe vaginal complications after birth and better
fetal outcomes among breech presentations. It is also more expensive.
(1) However, because of the complex nature of decisions about mode of
birth and the uncertainty about outcomes, randomised controlled trials
are unlikely to provide definitive answers about which mode of birth is
best for a particular woman. Future work should help to establish a
consistent set of probabilities for a range of outcomes, according to
risk factors, to inform women's decisions. (2) One response argues
that a large, prospective, long-term study is needed to compare outcomes
for women without absolute indications for caesarean who plan to give
birth by caesarean versus those who plan to give birth vaginally.
Another response points out that we should be trying to avoid the two
most damaging delivery methods in terms of maternal mental
health--emergency caesareans and traumatic vaginal deliveries. (3)
(1.) Villar J, Carroli G, Zavaleta N, et al. Maternal and neonatal
individual risks and benefits associated with caesarean delivery:
multicentre prospective study. BMJ 2007;335:1025-29.
(2.) Shorten A. Maternal and neonatal effects of caesarean section:
more accurate estimates of benefits and harms are needed to support
informed childbirth choices. BMJ 2007;335:1003-04.
(3.) Davies S. Caesarean section: points raised in responses. BMJ