Are There Sleep-related Factors That Contribute to an Increased Incidence of Pre-eclampsia at Altitude?

Women at altitude have an increased incidence of pre-eclampsia. Populations at altitude have a greater incidence of sleep apnea. And women with sleep apnea are at increased risk of developing preeclampsia. This research project will recruit for home sleep testing: healthy pregnant women at altitude (Summit County , Colorado at 9000 ft.), and women with preeclampsia at altitude, in order to learn whether either sleep apnea or nocturnal hypoxemia is more common or more severe in women with preeclampsia, than in healthy women at altitude. In addition a healthy co-hort of pregnant women will be studied at sea level, to compare to the healthy cohort of pregnant woman in Summit County, to learn to degree that this difference in altitude effects the severity of sleep apnea and hypoxemia.