Optimal Mode of Delivery for Individuals With Low-Risk Term Breech Presentation.

OBJECTIVE

To evaluate the risks of neonatal and maternal adverse outcomes in individuals with low-risk, singleton, term breech presentation associated with vaginal compared with cesarean delivery in a contemporary cohort in the United States.

METHODS

We conducted a propensity score analysis to evaluate adverse neonatal and maternal outcomes associated with mode of delivery among individuals with breech presentation at term. We used U.S. vital statistics data, which included information on all live births from 2015 to 2020. The eligible cohort was restricted to individuals who delivered a liveborn singleton, nonanomalous neonate at term. The treatment was vaginal or cesarean delivery. Composite neonatal and maternal outcomes were examined using a propensity score analysis to create groups based on mode of delivery with a 5-to-1 match of cesarean to vaginal deliveries. The composite neonatal outcome included neonatal mortality, 5-minute Apgar score less than 4, seizures or serious neurologic dysfunction, neonatal intensive care unit admission, or assisted ventilation 6 hours or longer. The composite maternal outcome included uterine rupture, maternal transfusion, intensive care unit admission, unplanned hysterectomy, or perineal lacerations.

RESULTS

Of 23,118,953 singleton births, 375,500 term, nonanomalous, breech live births were identified. Of these, 5.1% (95% CI, 5.0-5.2; n=19,256) were vaginal deliveries. After propensity score matching, the final cohort comprised 96,095 patients, including 17,558 vaginal deliveries and 78,537 cesarean deliveries. The risks of the composite adverse neonatal outcome were 7.2% in the vaginal delivery group, compared with 6.3% in the cesarean delivery group (risk difference [RD] 1.0; 95% CI, 0.9-1.2; doubly robust odds ratio 1.14; 95% CI, 1.06-1.22). The primary contributor to neonatal morbidity within the vaginal breech cohort was 5-minute Apgar score less than 4 (RD 1.6; 95% CI, 1.4-1.9). Other neonatal outcomes were not different. Neonatal mortality rates were 0.4% (n=67) for vaginal births and 0.1% (n=102) for cesarean births (RD 0.3; 95% CI, 0.2-0.4). The risk of the composite adverse maternal outcome (excluding perineal lacerations) was 0.3% for vaginal births and 0.5% for cesarean breech births (RD -0.4, 95% CI, -0.5 to -0.3).

CONCLUSION

Although term vaginal breech delivery was associated with slightly higher odds of the composite adverse neonatal outcome compared with cesarean delivery, the absolute risk remains low. Short-term maternal outcomes were better for individuals who underwent vaginal delivery compared with cesarean delivery, after exclusion of perineal lacerations.