Association between mode of delivery and infant survival at 22 and 23 weeks of gestation.

Background: Cesarean delivery is currently not recommended before 23 weeks' gestation unless for maternal indications, even in the setting of malpresentation. These recommendations are based on a lack of evidence of improved neonatal outcomes and survival following cesarean delivery and the maternal risks associated with cesarean delivery at this early gestational age. However, as neonatal resuscitative measures and obstetrical interventions improve, studies evaluating the potential neonatal benefit of periviable cesarean delivery have reported inconsistent findings.

Objective: This study aimed to compare the survival rates at 1 year of life among resuscitated infants delivered by cesarean delivery with those delivered vaginally at 22 and 23 weeks of gestation.

Study Design: We conducted a population-based cohort study of all resuscitated livebirths delivered between 22 0/7 and 23 6/7 weeks of gestational age in the United States between 2007 and 2013. The primary outcome was the rate of infant survival at 1 year of life for different routes of delivery (cesarean vs vaginal delivery) at both 22 and 23 weeks of gestation. The secondary outcome variables included infant survival rates for neonates who survived beyond 24 hours of life, neonatal survival, and the length of survival. A secondary analysis also included a comparison of the infant survival rates between the different routes of delivery cohorts stratified by fetal presentation, steroid exposure, and ventilation. Information about composite adverse maternal outcomes were limited to infants who were delivered between 2011 and 2013 (when these items were first reported) and were defined as a requirement for blood transfusion, an unplanned operating room procedure following delivery, unplanned hysterectomy, and intensive care unit admission; the composite adverse maternal outcomes were also compared between the different delivery route cohorts for deliveries occurring between 22 and 23 weeks of gestation. Multivariable logistic regression analysis was used to determine the association between cesarean delivery and infant survival and other neonatal and maternal outcomes.

Results: Resuscitated infants delivered by cesarean delivery had higher rates of survival at 22 weeks (44.9 vs 23.0%; P<.001) and at 23 weeks (53.3 vs 43.4%; P<.001) of gestation regardless of fetal presentation. Multivariable logistic regression analysis demonstrated that infants who were delivered by cesarean delivery at 22 weeks (adjusted relative risk, 2.3; 95% confidence interval, 1.9-2.8) and 23 weeks (adjusted relative risk, 1.4; 95% confidence interval, 1.2-1.5) of gestation were more likely to survive than those delivered vaginally. When the cohort was limited to neonates who survived beyond the first 24 hours of life, vertex neonates born by cesarean delivery were not more likely to survive at 22 weeks (adjusted relative risk, 1.2; 95% confidence interval, 0.9-1.7) or 23 weeks (adjusted relative risk, 1.1; 95% confidence interval, 0.9-1.3) of gestation. An increased risk for composite adverse maternal outcomes (adjusted relative risk, 1.7; 95% confidence interval, 1.1-2.7) was associated with cesarean delivery at 22 to 23 weeks of gestation.

Conclusion: Cesarean delivery is associated with increased survival at 1 year of life among resuscitated, periviable infants born between 22 0/7 and 23 6/7 weeks of gestation, especially in the setting of nonvertex presentation. However, cesarean delivery is associated with increased maternal morbidity.