Purpose: To ascertain any differences in foetomaternal outcomes in induced and spontaneous labour among nulliparous women delivering at term.
Methods: A retrospective matched cohort study consisting of 403 nulliparous women induced at ≥ 292 days and 806 nulliparous women with spontaneous labour at 285-291 days.
Results: Compared to those in spontaneous labour, women who had induction of labour were three times more likely to have a caesarean delivery (OR 3.1, 95% CI 2.4-4.1; P < 0.001). Women who had induction of labour were 2.2 times more likely to have oxytocin augmentation (OR 2.2, 95% CI 1.7-2.8; P < 0.001), 3.6 times more likely to have epidural anaesthesia (OR 3.6, 95% CI 2.8-4.6; P < 0.001), 1.7 times more likely to have uterine hyperstimulation (OR 1.7, 95% CI 1.1-2.6), 2 times more likely to have a suspicious foetal heart rate trace (OR 2.0, 95% CI 1.5-2.6), 4.1 times more likely to have blood loss over 500 ml (OR 4.1, 95% CI 2.9-5.5; P < 0.001), and 2.9 times more likely to stay in hospital beyond 5 days (OR 2.9, 95% CI 1.5-5.6; P < 0.001). Babies born to mothers who had induction of labour were significantly more likely to have an Apgar score of <5 at 5 min and an arterial cord pH of <7.0.
Conclusion: Compared to those with spontaneous labour, nulliparous women with induced labours are more likely to have uterine hyperstimulation, caesarean delivery, and babies with low Apgar scores. Nulliparous women should be made aware of this, as well as potential risks of expectant management during counseling.