Effects of maternal obstructive sleep apnea on fetal growth: a case-control study.

Objective: To investigate whether maternal obstructive sleep apnea (OSA) is associated with changes in fetal growth trajectory.

Study Design: Retrospective review of pregnant women who underwent overnight polysomnography. Fetal growth was estimated using sonographic biometric measurements obtained during routine prenatal care. Customized estimated fetal weight and birth weight centiles were calculated and impaired fetal growth was defined as birth weight <10th centile or a slowing of fetal growth by >33% during the last trimester. Logistic regression models were used to determine the relationship between maternal OSA and altered fetal growth after adjusting for potential covariates.

Results: There were 48 women without and 31 women with OSA. There were no differences in the proportion of infants with birth weight <10th centile between women with and without OSA (23 vs. 25%, p = 1.0), However, the presence of maternal OSA was predictive of impaired fetal growth (aOR 3.9, 95% CI 1.2-12.6). Logistic regression models were repeated using only a slowing of fetal growth in the 3rd trimester (excluding birth weight <10th centile) and OSA predicted a slowing in fetal growth across the 3rd trimester (aOR 3.6, 95% CI 1.4-9.4). Fourteen additional women were treated with positive airway pressure during pregnancy; fetal growth was not significantly different in these women compared to controls.

Conclusion: Obstructive sleep apnea is independently associated with altered fetal growth, which appears to be ameliorated with use of positive airway pressure.