Prospective, randomized controlled trial. Pregnant women in early pregnancy will be randomized to either the Sleep Study + CPAP group (n = 180) or to a Standard Prenatal Care group (n = 180). Subjects in the Sleep Study + CPAP group will complete a sleep study (WatchPAT-200, Itamar Medical, Inc.) and have CPAP initiated if the AHI ≥5 as indicated, in early and late pregnancy, whereas the other group will receive standard prenatal care. All subjects will complete a sleep study again at 12 weeks postpartum.