Risk of birth defects in pregnant persons with sleep-disordered breathing during pregnancy

As many as one in four pregnant women may experience sleep-disordered breathing (SDB) during pregnancy. The same sequelae of SDB, such as insulin resistance and inflammation, have been implicated in the development of certain birth defects.

This is a secondary analysis of the SDB substudy of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be study, which included 2106 participants who had a sufficiency sleep study at two visits at different time points in pregnancy. SDB was based on a self-administered home sleep apnea test with data scored by trained, blinded research polysomnologists. SDB was defined as an apnea-hypopnea index (AHI) ≥5. The primary outcome of this analysis was any of the 45 non-chromosomal birth defects included in the National Birth Defects Prevention Network Annual Report.

In this cohort, the overall rate of birth defects was 3.1%. The prevalence was similar between those without SDB (3.0%) and those with only mid-pregnancy SDB (3.4%), but was higher in those with early-pregnancy SDB (6.7%). After adjusting for maternal age, chronic hypertension, pregestational diabetes, and body mass index (BMI), there were no statistically significant differences in the risk of birth defects by subject SDB status.

Further studies to evaluate the effect of prepregnancy and early-pregnancy SDB on the fetus, as well as the risk of specific birth defects and neonatal outcomes in those with an objectively measured diagnosis of SDB, are still needed.