Differences on risk of cesarean section after labour induction according different portuguese hospitals

Abstract

To assess if the risk of caesarean section (CS) after labour induction (LI) differs between hospitals and which extent this association may explain differences in CS rates. Methods: Participants (6688 Portuguese women) were consecutively recruited in five public hospitals (level III) during the assembling of a birth-cohort. Personal interviews were used to obtain data on socio-demographic characteristics, gynecological history and obstetric events. The risk (computed as odds ratio (OR) and 95% confidence Interval (95%CI)) of CS were considered according to hospital and adjusted for socio-demographic and obstetric characteristics. An interaction term (hospital and LI) was considered in the final model. Results: The proportion of LI by hospital ranged from 15.8% to 53.5% (p<0.001) and the proportion of CS varied between 22.2% and 35.6% (p<0.001). Women with LI presented an higher adjusted rate of CS (OR=1.71; 95%CI:1.48-1.99). There was a statistically significant interaction between hospital and IL on the risk of CS (p=0.002). After stratification by hospital and adjustment to characteristics of mother, the risk of CS for women with LI in comparison with those without LI was higher for three hospitals (OR=3.15; 95%CI:1.98-5.04, OR=1.84; 95% CI:1.38-2.46 and OR=2.04; 95%CI:1.52-2.73) but no such effect was found in the remaining two. Conclusions: Different associations between LI and CS across hospitals probably result from different management of LI. These differences may partially explain discrepancies in CS rates across hospitals.