Vaginal birth after caesarean section versus elective repeat caesarean section: assess neonatal downstream outcomes too



We were interested in the article by Pare et al.1 showing an excess increase in hysterectomy in subsequent pregnancies for women having elective repeat caesarean sections. Further valuable information is added to the risk assessment which women, obstetricians and midwives must make; both when considering a primary caesarean section or waiting for labour in a subsequent pregnancy. The National Institute of Clinical Excellence has examined the health risks of caesarean section and concluded that, even for a first caesarean section, maternal request alone is not an indication for elective major surgery and requires the use of counselling to explore women’s motives and a second opinion,2 because of the imbalance of health risks to mothers and babies which only widens with increasing parity and increasing numbers of caesarean sections. It is generally better to labour (even if that ends in emergency caesarean section) and especially in settings that achieve high vaginal delivery rates. This is not only because of the future maternal morbidity that repeat caesarean sections cause (which can only increase as the caesarean rate rises) but also because of increasing risks to babies. Poor fetal outcomes are sometimes used to justify avoiding vaginal birth after caesarean sections (VBAC) entirely or to avoid VBAC at home or in midwifery-led childbirth centres in particular. For example, VBACs in childbirth centres were eliminated in the USA based on an increase of 1/1000 perinatal deaths among women having a VBAC after one caesarean section in childbirth centres3 despite higher successful vaginal birth rates. But logic would suggest that for those women planning or experiencing further pregnancies, VBAC after one caesarean section may be safer overall in a childbirth centre than in the hospital. This is because childbirth centres had a mean 87% successful VBAC rate compared with 10% in US hospitals.3 The UK has an overall 33% VBAC rate.4 Intrapartum perinatal mortality due to uterine rupture during labour has to be balanced against reports suggesting an increase in third trimester unexplained stillbirths in future pregnancies following caesarean sections. Although no one has yet examined the rate of unexplained third trimester stillbirths after two or more caesarean sections, the rate of unexplained stillbirths after one caesarean section has been shown to be 1/500 versus 1/1000 after one vaginal birth5 in observational studies. If this association of caesarean sections with subsequent stillbirth is confirmed, it is a fetal argument against elective repeat caesarean sections. One theory suggests that the unexplained fetal demise is a complication resulting from the uterine scar, although a plausible mechanism is as yet unknown. Thus, it is possible that the rate of unexplained stillbirths may increase even further with increasing numbers of scars and, in any case, would not be expected to decrease. When an increased risk of stillbirth is added to the excess increase in hysterectomy1 and long-established respiratory risks of elective caesarean section, it is at least arguable that childbirth centres may statistically be a safer place for women after one caesarean section who wish to have more children, unless and until hospitals match their typical 87% successful VBAC rate. Of course, using a childbirth centre in the first labour and avoiding the first caesarean section might be the best overall preventative approach for the health of mothers and babies.