Obstructive sleep apnea is known to be a significant source of morbidity in the general population. It has been proposed to be associated with the development of preeclampsia and fetal growth restriction. As these are conditions that have long term maternal and neonatal implications, further information may help improve maternal/fetal outcome. One reason why women and in particular pregnant women are under diagnosed is the lack of an effective, reliable screening tool. Validated questionnaires used in the general population may not be effective in screening pregnant women. The investigators hypothesize that sleep apnea will have 20% prevalence in the obese pregnant population and that it is associated with increased maternal and neonatal morbidity. The investigators will recruit obese pregnant women in their prenatal care clinics and they will be screened for OSA using validated sleep questionnaires including the Epworth sleepiness scale, the Fatigue Scale and the Berlin Questionnaire. The subjects will then perform overnight apnea monitoring utilizing a portable sleep apnea detection device. Women who meet clinical criteria for OSA will be referred for overnight polysomnogram and management by the Pulmonary and Critical Care Division of the Internal Medicine Department. For all enrolled patients the remainder of prenatal care will be per routine. Data will be collected regarding the pregnancy course and outcomes.

The primary outcome of interest is the prevalence of sleep apnea in obese women and the associated maternal and neonatal morbidity. The secondary outcome measures will be molecular measures of systemic inflammation, oxidative stress and angiogenesis associated with sleep apnea.

Inclusion Criteria:

• Prepregnancy BMI of 30kg/m2 or greater
• Singleton pregnancy
• 18 years or older

Exclusion Criteria:

• Chronic use of narcotics or other CNS drugs
• Inability to sleep beyond 2 hours
• 3 or more missed prenatal visits

Obstetric care clinic at a tertiary care hospital