In uncomplicated twin pregnancies where the first twin presentation was cephalic, perinatal and maternal outcomes were similar whether the birth plan was for vaginal or abdominal delivery, a large study has found.

Between December 2003 and April 2011, 2,804 women with twin pregnancies were recruited in 25 countries, including the UK. All 106 participating centres were staffed by experienced obstetricians with rapid access to operative intervention during labour.

All pregnancies were otherwise uncomplicated and with the first twin presenting head first. All were randomised between the 32nd and the 38th completed week of pregnancy to either planned CS or vaginal delivery.

Of the 1,398 randomised to CS, 89.9% underwent this method of delivery, 9.3% had a vaginal delivery and 0.8% had both (i.e. vaginal delivery of twin 1 and CS for twin 2). More than half (59.2%) of sections were performed before the start of labour. Of the 1,406 randomised to vaginal delivery, 56.2% had a vaginal birth, 39.6% had CS and 4.2% had both. Two-thirds (67.5%) of sections in this group were carried out during labour.

Perinatal morbidity was assessed looking particularly at trauma, sepsis, neurological complications and necrotising enterocolitis. Perinatal complications occurred in 2.2% of those randomised to CS and 1.9% of those randomised to vaginal delivery, OR 1.16 (95% CI:0.77-1.74, P = 0.49). The composite fetal/neonatal mortality and serious neonatal morbidity rate was higher for the second twin compared with the first, OR 1.9 (95% CI:1.3-2.69, P < 0.001). There was, however, no significant difference between the two randomisation groups.

Post-partum haemorrhage and perineal trauma rates were higher in the planned vaginal delivery group and DVT/PE, wound dehiscence and sepsis were more common in the planned CS group. However, none of these reached a statistically significant level. The composite maternal mortality and serious morbidity rates were 8.5% for planned vaginal and 7.3% for planned CS delivery (P = 0.29).

This large well organised trial has shown that in otherwise uncomplicated twin pregnancies where the first twin presentation was cephalic, perinatal and maternal outcomes were similar whether the birth plan was for vaginal or abdominal delivery. Planned CS did not appear to improve outcomes.

Dr Chris Barclay