Risks of induction of labour in women with a uterine scar from previous low transverse caesarean section.

OBJECTIVE: Recent studies have shown that among women with uterine scars from previous caesarean section of any type, induction of labour is associated with increased risk of uterine rupture compared with spontaneous labour. We have assessed the risk of uterine rupture in a cohort of women with a previous low transverse caesarean section in whom induction and management of labour were performed according to a strict protocol. DESIGN: Cohort study. SETTING: University Hospital. POPULATION: All women with a singleton pregnancy and a previous low transverse caesarean section requiring induction of labour from 1/1/1992 to 12/30/2001 (n = 310) were compared with a control cohort during the same study period constituted of women with a previous low transverse caesarean section in spontaneous labour (n = 1011). METHODS: Clinical characteristics and rate of uterine rupture of women with previous caesarean section undergoing induction of labour were compared with those of women with previous caesarean section in spontaneous labour. MAIN OUTCOME MEASURE: Incidence of uterine rupture. RESULTS: Uterine rupture occurred in 0.3% in the previous caesarean section--induction group versus 0.3% in the previous caesarean section--spontaneous labour group (P = 0.9). Logistic regression analysis showed no significant difference in the rate of uterine rupture between the induction and spontaneous labour group (P = 0.67) after controlling for maternal age, parity, duration of labour, gestational age at delivery and birthweight. CONCLUSION: Among women with a previous low transverse caesarean section, induction of labour is not associated with significantly higher rates of uterine rupture compared with spontaneous labour, provided a consistent protocol with strict criteria for intervention is adopted.