Sleep Disordered Breathing and Efficacy of Nasal CPAP in Women at Risk for Preeclampsia: A Pilot Study

Sleep-disordered breathing is on a continuum from occasional snoring to interrupted breathing (apneas) and is associated with abdominal weight gain and hypertension in adult men and post-menopausal women. To date, prospective research on sleep in pregnancy has either been limited to small numbers, done at the time of labor onset, or only assessed in the week prior to birth. However, if sleep is assessed earlier in gestation, before the dramatic weight gain or onset of pregnancy-induced hypertension, there is a potential opportunity to minimize sleep loss and reverse possible pathophysiological effects associated with sleep disordered breathing on the mother and the fetus. Moreover, since the prevalence of sleep disturbance increases with gestation, assessment of sleep in the third trimester does not provide a clear understanding of sleep disturbances known to occur earlier in pregnancy. Previous research has demonstrated a high correlation between self-report and objective measures of sleep using wrist activity during the third trimester of pregnancy. Therefore, we will prospectively describe the sleep quality, daytime sleepiness, and fatigue symptoms reported by women in the second trimester of pregnancy and explore associations with later perinatal outcomes. If there are significant associations with perinatal outcomes, this information can be used to educate obstetric providers about the need for screening and referral of women with sleep symptoms for diagnostic evaluation and treatment. Those with clinical indicators of sleep-disordered breathing, hypertension, or obesity will be selected for further sleep assessment using polysomnography.

Polysomnography (PSG) is the gold standard for identifying sleep-related respiratory disturbances. PSG will be used to more closely assess the subsample of women designated to be high-risk for pre-eclampsia to identify both the extent of sleep disordered breathing (SDB) experienced by women in the second trimester and those in need of nasal continuous positive airway pressure (CPAP) to treat their sleep disordered breathing, minimize the effects of preeclampsia on the maternal-fetal dyad, and prolong gestation. Identifying biomarkers associated with both sleep disordered breathing and preeclampsia will allow for an improved understanding of the biological precedents associated with certain perinatal outcomes.

Currently there is no known strategy to prevent the development of preeclampsia. Although there are known risk factors associated with preeclampsia, most are unmodifiable. CPAP has been shown to decrease blood pressure in non-pregnant populations and been shown in the third trimester to moderate night-time elevated blood pressure in women with pre-eclampsia3 Both preeclampsia and sleep-related respiratory disturbances appear to result in (or result from) similar inflammatory responses. We will explore acceptability of the use of nasal CPAP in pregnancy and whether it can effectively reverse or modulate physiological inflammatory effects of sleep disordered breathing, and therefore decreasing the risk of developing preeclampsia among women who are at high-risk or at least prolong gestation closer to full-term.