Association between gestational age and severe maternal morbidity and mortality of preterm cesarean delivery: a population-based cohort study

Background: Cesarean delivery rates at extreme prematurity have regularly increased over the past years, and few previous studies have investigated severe maternal morbidity associated with extreme preterm cesarean delivery.

Objective: The aim of this study was to evaluate whether gestational age <26 weeks of gestation (weeks) was associated with severe maternal morbidity and mortality (SMMM) of preterm cesarean deliveries in comparison with cesarean deliveries between 26 and 34 weeks.

Materials and methods: The Etude Epidémiologique sur les petits âges gestationnels (EPIPAGE) 2 is a national prospective population-based cohort study of preterm births in 2011. We included mothers with cesarean deliveries between 22 and 34 weeks, excluding those who had a cesarean delivery for the second twin only and those with pregnancy terminations. SMMM was analyzed as a composite endpoint defined as the occurrence of at least 1 of the following complications: severe postpartum hemorrhage defined by the use of a blood transfusion, intensive care unit admission, or death. To assess the association of gestational age <26 weeks and SMMM, we used multivariate logistic regression and a propensity score-matching approach.

Results: Among 2525 women having preterm cesarean deliveries, 116 before 26 weeks and 2409 between 26 and 34 weeks, 407 (14.4%) presented with SMMM. The SMMM occurred in 31 mothers (26.7%) who were at gestational age <26 weeks vs 376 (14.2%) between 26 and 34 weeks (P < .001). Cluster multivariate logistic regression showed significant association of gestational age <26 weeks and SMMM (adjusted odds ratio [aOR], 2.50; 95% confidence interval [CI], 1.42-4.40) and propensity score-matching analysis was consistent with these results (aOR, 2.27; 95% CI, 1.31-3.93).

Conclusion: Obstetricians should know about the higher SMMM associated with cesarean deliveries before 26 weeks, integrate this knowledge into decisions regarding cesarean delivery, and be prepared to manage the associated complications.