Machine learning prediction models for mode of delivery in prolonged pregnancies in Sweden

Induction of labour and not "expectant management" is often recommended to prevent adverse perinatal outcomes in late-term pregnancies, but no prognostic prediction model exists for an individualized decision-making. The present study used a data-driven approach to predict mode of delivery at or beyond 41 gestational weeks considering the obstetric management. Low-risk nulliparous women were derived from the nationwide Swedish Medical Birth Register (1998-2019). A two-day-wise prediction in four study groups with increasing gestational age (e.g. group 1: induced at 41⁺⁰-41⁺¹, expectant management beyond 41⁺¹ gestational weeks) was conducted. Forty-three features available at the time for decision-making on labour induction in each subgroup were used in the models, including the decision on labour induction itself. The subgroups contained 178,932, 129,449, 90,448 and 61,301 pregnancies, respectively, with imbalanced outcome rates (cesarean delivery < 27%, spontaneous birth > 55%, vaginal operative delivery < 18%). Five different classifiers were compared (random forest, mixed naïve bayes, support vector machine, neural network, logistic regression) with the highest value of the area under the curve being 69% in a hold-out sample. Although the considered features lacked predictive power, the study provides valuable methodological information for predicting the timing of labour induction beyond 41 gestational weeks.