Objective: To examine indications for the induction of labour and variations in the current policy of induction at different levels of obstetric specialisation and to compare the outcome of induced and spontaneous labour.
Design: A prospective 1 year birth cohort.
Setting: Maternity hospitals in the two northernmost administrative provinces of Finland, including one university hospital and three central hospitals, three local hospitals and five health centres.
Subjects: Eight thousand six hundred and six singleton pregnancies, including 1679 with induced labour.
Main outcome measure: Data collection on age, parity, social factors and education at antenatal clinic. Data on labour collected from the hospital records after delivery.
Results: Labour was induced significantly more often at units of the lowest level of specialisation, the health centres (29.4%) than at the local hospitals (23.6%, P < 0.003) or in the most specialised central hospitals (17.7%, P < 0.0001). Cases of induced labour accumulated on working days. Indicative reasons, such as maternal or fetal conditions, comprised 45.0% of the indications for induction, the most common causes being elective reasons, e.g. timing of labour (51.3%). The risk of elective induction was 2.6 times greater at the primary care level than at the central hospitals (95% confidence limit, CL 2.0-3.2). The corresponding risk ratio for local hospitals was 1.8 (CL 1.5-2.1). The risk of caesarean section was 1.5 times greater in the elective induction group than in the spontaneous group (CL 1.1-1.9) and 2.9 times greater in the indicative induction group. The most common indication for caesarean section was dysfunctional, arrested labour, causes such as fetal asphyxia or antenatal haemorrhage were not seen in excess.
Conclusion: The practice of induction of labour are not consistent in different hospitals. The opinions of individual practitioners and staff routines influence the induction policy nearly as much as do medical reasons. Despite the safety of induction, a liberal induction policy leads to an increase in operative deliveries creating potential risks for the mother and child and greater expense.