The Edmonton Obesity Staging System Predicts Mode of Delivery After Labour Induction

This study sought to evaluate the use of the Edmonton Obesity Staging System (EOSS) in predicting cesarean delivery among term, nulliparous, singleton pregnancies in women with overweight or obesity who are undergoing an induction of labour.

A prospective cohort study was performed in Edmonton, Alberta. Women undergoing an induction of labour at term were recruited to either a sample cohort, including women with a body mass index of ≥25 kg/m² at first antenatal visit, or a control cohort with a body mass index of 18.5 to 24.9 kg/m². Participating women provided a self-reported health history and consented to review of their medical records allowing allocation into EOSS categories. The primary outcome was the rate of cesarean delivery based on EOSS category. Secondary outcomes consisted of a summary score of adverse maternal, delivery, and neonatal events (Canadian Task Force Classification II-2).

Overall, 345 women were recruited, with a participation rate of 93.7%. The sample cohort consisted of 276 women with overweight or obesity, whereas the control cohort included 69 normal-weight women. The overall rate of cesarean delivery was 30.4% for the control cohort and 35.8%, 29.9%, 43.2%, and 90.5% for women assigned an EOSS category 0, 1, 2, and 3, respectively (P < 0.001). A summary score was not indicative of overall rate of adverse maternal, delivery, and neonatal events (P = 0.22).

The EOSS may help predict the chance of cesarean delivery in a high-risk group of nulliparous women with overweight or obesity who are undergoing an induction of labour at term.