Caesarean births doubles the risk of death and illness for mother and baby

29  October 2007

Women having a non-emergency caesarean birth have double the risk of illness or even death compared to a vaginal birth, according to a study published online on Wednesday 31 October by the British Medical Journal.

'A multicentre prospective study to evaluate maternal and neonatal risks and benefits associated with caesarean delivery,’ led by Dr Jose Villar, Senior Fellow in Perinatal Medicine at the Department of Obstetrics and Gynaecology, Oxford University, has found that while caesarean delivery reduces the overall risk in breech births, the risk of maternal and neonatal deaths increases in caesareans for cephalic presentations (head-first position).

The risks linked to caesarean births (whether chosen by the woman or her clinicians) are higher regardless of variables such as demographics, medical and pregnancy history, gestational age of the foetus, pregnancy complications, where the baby is born, and the skills of those helping to deliver the baby.

The study used data from the Latin American component of the World Health Organisation ‘Global Survey on Maternal and Perinatal Health,’ collected in 2005. Researchers randomly selected eight Latin American countries and from those, 120 randomly selected health facilities provided complete data on 97,307 deliveries of babies during a three-month study period. 33.7 per cent of the births were caesarean, and 66.3 per cent vaginal. The overall perinatal outcomes in these hospitals good, similar to most large hospitals in developed countries.

The researchers focused on maternal, foetal, and neonatal morbidity and mortality associated with intrapartum caesarean, where a caesarean takes place once labour has begun, and elective caesarean, before the onset of labour. A woman having a caesarean delivery had twice the risk of illness and mortality (including death, hysterectomy, blood transfusion and admission to intensive care), than a woman having a vaginal delivery.

The risk of antibiotic treatment after birth for women having either type of caesarean was five times higher than those having vaginal deliveries. For babies in the head-first position, the risk of having to stay in a neonatal intensive care unit doubled after a caesarean delivery compared to a vaginal birth.

The authors also found that the risk of neonatal death was significantly increased (more than 70 per cent higher) for babies in the head-first position from both an elective and a clinician- chosen caesarean, compared to a vaginal delivery.

Dr Jose Villar said: ‘The liberal use of caesarean delivery (with the exception of women carrying breech babies) does not necessarily reflect best quality practice; indeed it may do more harm than good, and cost health services more. Women and their partners should be advised accordingly. A rigorous assessment of current practice in those units providing this pattern of care, focusing specifically on case mix and outcomes is suggested.’

However, the study does show that among breech presentations, caesarean delivery leads to fewer severe vaginal complications, and has a large protective effect for foetal death.

An accompanying editorial says that more accurate estimates of probabilities from other populations are needed to support informed childbirth choices.

For more information please contact Dr Jose Villar on (01865) 857942, or (01865) 221003, or at jose.villar@obs-gyn.ox.ac.uk.