Association Between Sleep-Disordered Breathing and Hypertensive Disorders of Pregnancy and Gestational Diabetes Mellitus

Abstract

Objective: To estimate whether sleep-disordered breathing during pregnancy is a risk factor for the development of hypertensive disorders of pregnancy and gestational diabetes mellitus (GDM).

Methods: In this prospective cohort study, nulliparous women underwent in-home sleep-disordered breathing assessments in early (6-15 weeks of gestation) and midpregnancy (22-31 weeks of gestation). Participants and health care providers were blinded to the sleep test results. An apnea-hypopnea index of 5 or greater was used to define sleep-disordered breathing. Exposure-response relationships were examined, grouping participants into four apnea-hypopnea index groups: 0, greater than 0 to less than 5, 5 to less than 15, and 15 or greater. The study was powered to test the primary hypothesis that sleep-disordered breathing occurring in pregnancy is associated with an increased incidence of preeclampsia. Secondary outcomes were rates of hypertensive disorders of pregnancy, defined as preeclampsia and antepartum gestational hypertension, and GDM. Crude and adjusted odds ratios and 95% confidence intervals (CIs) were calculated from univariate and multivariate logistic regression models.

Results: Three thousand seven hundred five women were enrolled. Apnea-hypopnea index data were available for 3,132 (84.5%) and 2,474 (66.8%) women in early and midpregnancy, respectively. The corresponding prevalence of sleep-disordered breathing was 3.6% and 8.3%. The prevalence of preeclampsia was 6.0%, hypertensive disorders of pregnancy 13.1%, and GDM 4.1%. In early and midpregnancy the adjusted odds ratios for preeclampsia when sleep-disordered breathing was present were 1.94 (95% CI 1.07-3.51) and 1.95 (95% CI 1.18-3.23), respectively; hypertensive disorders of pregnancy 1.46 (95% CI 0.91-2.32) and 1.73 (95% CI 1.19-2.52); and GDM 3.47 (95% CI 1.95-6.19) and 2.79 (95% CI 1.63-4.77). Increasing exposure-response relationships were observed between apnea-hypopnea index and both hypertensive disorders and GDM.

Conclusion: There is an independent association between sleep-disordered breathing and preeclampsia, hypertensive disorders of pregnancy, and GDM.

Figures

Figure 1

Flowchart showing enrollment in nuMoM2b sleep-disordered breathing substudy and inclusion in analysis. *For the 728 women (3,550 minus 2,822) without sleep studies in mid-pregnancy, 30 had a preterm birth before the sleep study could be completed, 86 missed the study visit (including the sleep assessment), and 612 had the study visit but did not participate in the mid-pregnancy sleep study. In planning the study, it was assumed that 25% would refuse the second sleep study. The participation rate in the mid-pregnancy sleep study was higher than expected. nuMoM2b, Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be; IQR, interquartile range.

Figure 2

The distributions of the women by apnea-hypopnea index (AHI) category in early and mid-pregnancy are presented, giving point estimate (95% confidence interval). *Mild sleep-disordered breathing. †Moderate or severe sleep-disordered breathing.