Objective
The objective of the Sleep Disordered Breathing substudy of the Nulliparous Pregnancy Outcomes Study Monitoring Mothers-to-be (nuMoM2b) is to determine whether sleep disordered breathing during pregnancy is a risk factor for adverse pregnancy outcomes.
Methods
nuMoM2b is a prospective cohort study of 10,037 nulliparous women with singleton gestations, conducted across 8 sites, with a central Data Coordinating and Analysis Center. The Sleep Disordered Breathing substudy recruited 3702 women from the cohort to undergo objective, overnight in-home assessments of sleep disordered breathing. A standardized Level 3 home sleep test was performed between 60–150 weeks of pregnancy (Visit 1) and again between 220–310 weeks of pregnancy (Visit 3). Scorings of tests were conducted by a central Sleep Reading Center. Participants and their health care providers were notified if test results met “urgent referral” criteria based on threshold levels of apnea hypopnea indices, oxygen saturation levels or ECG abnormalities, but otherwise were not notified of test results. The primary pregnancy outcomes to be analyzed in relation to maternal sleep disordered breathing are preeclampsia, gestational hypertension, gestational diabetes, fetal growth restriction, and preterm birth.
Results
Objective data were obtained at Visit 1 on 3261 women, 88.1% of studies attempted; and at Visit 3 on 2511 women, 87.6% of studies attempted. Basic characteristics of the substudy cohort are reported in this methods paper.
Conclusion
The substudy is designed to address important questions regarding the relationship of sleep disordered breathing on the risk of preeclampsia and other outcomes of relevance to maternal and child health.