Background The issues related to safety of induction of labour in women with previous caesarean section remain controversial. The main adverse outcome fuelling this debate is a ‘small’ risk of uterine rupture that is potentially devastating for both the mother and the fetus.
Objective To estimate the risk of uterine rupture or dehiscence in women who require induction of labour with previous caesarean sections.
Design Five year retrospective review of computerised hospital records and case note review of index cases.
Setting Large inner city teaching hospital.
Population Two hundred and five women who had their labour induced with history of one lower segment caesarean section.
Methods This study was conducted at Liverpool Women's Hospital, a tertiary referral centre, with approximately 6000 births per annum. We searched the hospital's computerised records of deliveries from June 1997 to June 2002 and reviewed all indications and outcomes of induction of labour in women with one previous caesarean section. Women with singleton pregnancy and cephalic presentation were then divided into three groups: those with one previous caesarean section and no previous vaginal deliveries, those whose last delivery was a caesarean section but had delivered vaginally before and those whose last delivery was by vaginal route, but had had one caesarean section in the past.
Main outcome measures Uterine rupture or dehiscence, adverse neonatal outcome.
Results Two hundred and five women were included. There were four cases of uterine rupture and one dehiscence (2.4%, 95% CI 0.8–5.6%). Two babies were profoundly acidotic at birth, but all five neonates were healthy when discharged from hospital with no long term morbidity. All five cases occurred in the group of women with no previous vaginal deliveries. The intrauterine pressure catheter recordings had contributed to the diagnosis of uterine rupture/dehiscence in three out of five cases.
Conclusion In women with previous caesarean section and no vaginal deliveries, induction of labour carries a relatively high risk of uterine rupture/dehiscence despite all precautions, including intrauterine pressure monitoring.