Association Between Resident Involvement in Cesarean Delivery, Complications, and Operative Times

To evaluate whether resident physician involvement in cesarean delivery was associated with increased maternal or neonatal morbidity and increased operative times.

This was a secondary analysis of the Maternal-Fetal Medicine Units Network APEX (The Assessment of Perinatal Excellence) study, a multicenter observational cohort of deliveries occurring from 2008 to 2011. Participants with a nonanomalous, singleton, term cesarean were included. The exposure was resident involvement in cesarean delivery. The primary outcome was major maternal operative morbidity, defined as bowel or genitourinary injury, peripartum hysterectomy for uterine trauma, reoperation for bleeding or uterine trauma, wound dehiscence requiring reoperation, or maternal death. Secondary outcomes included a composite of minor maternal operative morbidity, a composite of neonatal morbidity, operative time from skin incision to delivery, and total operative time from incision to completion. Propensity scores were calculated from maternal demographics, comorbidities, and labor characteristics. Risk ratios were reported from average treatment effect on the treated (ATT)-weighted analysis, in which "treated" corresponds to patients for whom a resident was involved in their cesarean delivery.

Among 28,087 included deliveries, 73.8% (n=20,728) involved resident participation. In propensity-weighted models, resident involvement was not associated with major maternal operative morbidity (0.6% vs 0.4%, ATT-weighted relative risk [ATT RR] 1.24, 95% CI, 0.72-2.14). However, resident involvement was associated with a higher risk of minor maternal operative morbidity (5.4% vs 2.2%, ATT RR 1.88, 95% CI, 1.52-2.32), which was driven primarily by a higher incidence of postpartum hemorrhage requiring transfusion (5.0% vs 1.8%, respectively). Resident involvement was also associated with longer operative times from skin incision to delivery (8.5 minutes vs 6.9 minutes, ATT 22.7% longer duration, 95% CI, 20.4-25.0%) and from skin incision to skin closure (47.5 minutes vs 36.9 minutes, ATT 24.6% longer duration, 95% CI, 23.3-26.0%). Resident involvement was also associated with lower risk of neonatal morbidity (11.0% vs 10.0%, ATT RR 0.87, 95% CI, 0.79-0.96). In exploratory analyses examining the number of residents involved, results were similar in magnitude and direction to the primary analysis, regardless of whether two or three residents were compared with none or one resident was compared with none.

Resident involvement in cesarean deliveries was not significantly associated with major maternal morbidity such as organ injury, reoperation, or death. Although trainee involvement was associated with longer operative times and increased minor maternal morbidity, it was also associated with lower neonatal morbidity.