Background Induction of labour (IOL) is indicated when the perceived benefits of delivery outweigh the potential risks of continuing the pregnancy. At term, the risk to the fetus is minimal. However, for the mother, IOL may be associated with an increased risk of operative delivery.

Objectives To evaluate outcomes in women delivering at term after a spontaneous labour to those delivering after IOL during a 12 month period at Hinchingbrooke Hospital.

Methods Data were reviewed for all women delivering live singleton, term babies throughout 2012. Planned caesarean deliveries were excluded.

Results Of the 2101 eligible deliveries, the IOL rate was 30%. Emergency caesarean section (EMCS) rates were significantly higher following IOL than spontaneous labour (22% vs 9%, relative risk 2.2). EMCS was more frequent in nulliparous (18.4%) than multiparous women (8.6%). Instrumental delivery rates were equivalent following spontaneous labour (12%) or IOL (14%). IOL was associated with a greater incidence of major obstetric haemorrhage (>1500 ml); occurring in 6% and 2% of deliveries following IOL and spontaneous labour respectively. This difference was not accounted for by differences in caesarean section rates between the two groups.

Conclusion IOL was associated with poorer maternal outcomes than spontaneous labour. These risks are greater in nulliparous than multiparous women.

IOL rates are increasing which may reflect a lower threshold for intervention. Such consequences must be taken into consideration when deciding if IOL is indeed appropriate.