Predicting Route of Delivery Using Quantification of Maternal Expulsive Efforts in the Second Stage of Labor

To investigate the association between the number of pushing contractions and the likelihood of spontaneous vaginal delivery, operative vaginal delivery, cesarean delivery and maternal and neonatal complications.This was a retrospective analysis of patients who entered the second stage of labor with singleton, term pregnancies at Harbor-UCLA Medical Center from January 1, 2017, to December 31, 2019. Probabilities of spontaneous vaginal delivery, operative vaginal delivery, and cesarean delivery were calculated for each hour of pushing and for every 10 maternal pushing contractions. Maternal and neonatal morbidities were assessed in relation to second-stage pushing contractions.Four hundred thirty-nine nulliparous and 424 multiparous patients who entered the second stage of labor were included. Nulliparous patients had significantly more pushing contractions than multiparous patients (20.3±1.8 vs 7.8±1.0 pushes, P<.001). In nulliparous patients, 91.8% (326/355 patients) of spontaneous vaginal deliveries and 50.0% (12/24 patients) of cesarean deliveries occurred by 40 pushing contractions. In multiparous patients, 94.3% (369/391) of spontaneous vaginal deliveries and 50.0% of cesarean deliveries (4/8) occurred by 20 pushing contractions. The probabilities of cesarean delivery were at their highest after 80 pushing contractions in nulliparous patients and after 50 pushing contractions in multiparous patients. In both nulliparous and multiparous patients, there was no significant change in maternal and neonatal composite morbidities as the number of pushing contractions increased.Results from this study suggest that pushing contractions may be a viable alternative method for prediction of the likelihood of spontaneous vaginal delivery and probabilities of operative vaginal delivery and cesarean delivery for patients reaching the second stage of labor. Providing patients with a goal for expected number of pushing contractions may be of motivational benefit.