Reducing the caesarean delivery risk in elective inductions of labour: a decision analysis

To determine whether the vaginal delivery rate is increased in nulliparous women who have positive fetal fibronectin (fFN) testing before elective induction of labour, we performed a decision analysis that tested three options: (1) spontaneous labour; (2) testing nulliparous candidates for elective induction of labour at 39 weeks gestation with fFN and inducing labour if fFN positive (women who are fFN negative are managed expectantly); (3) elective induction of labour for women who are at least 39 weeks. We found that spontaneous labour had a vaginal delivery rate of 90, elective induction 79 and fFN screening 83. At baseline, a mother must be willing to take an additional 7 risk of caesarean delivery to warrant fFN testing or an additional 11 risk of caesarean delivery to warrant elective induction. We conclude that spontaneous labour has the highest vaginal delivery rates. An fFN test in a nulliparous woman may help to raise her likelihood of a vaginal delivery in an elective induction.