Syncope in pregnancy, immediate pregnancy outcomes, and offspring long-term neurologic health

There are limited data regarding the perinatal consequences of maternal syncope during pregnancy, and even less is known about the potential long-term effect on offspring health.

This study aimed to examine perinatal outcomes as well as long-term offspring neurologic morbidity associated with prenatal maternal syncope, and the possible differential effect by trimester of first syncope episode.

A retrospective cohort study was conducted, including all singleton deliveries occurring between 1991 and 2021 at a large tertiary medical center. Multivariable analyses were applied to study the associations between prenatal maternal syncope and various perinatal outcomes as well as offspring neurologic morbidity up to the age of 18 years, while adjusting for clinically relevant factors. Analyses were further conducted by trimester of first syncope episode.

The study population included 232,475 pregnancies, 774 (0.3%) were affected by maternal syncope, which most frequently first occurred during the second trimester (44.5%), followed by the first trimester (31.8%) and finally the third trimester (27.7%). Maternal syncope was independently associated with increased risk for intrauterine growth restriction (adjusted odds ratio, 1.52; 95% confidence interval, 1.01-2.29), which appeared to be mainly driven by first trimester syncope occurrence; as well as with increased risk for cesarean delivery (adjusted odds ratio, 1.33; 95% confidence interval, 1.10-1.61), and for long-term offspring neurologic morbidity (adjusted hazard ratio, 1.79; 95% confidence interval, 1.65-2.08), regardless of the trimester of syncope occurrence.

Prenatal maternal syncope is an independent risk factor for intrauterine growth restriction, cesarean delivery, and for long-term offspring neurologic morbidity.