UCSF

The majority of pregnancy sleep research has been conducted at sea level and relatively low elevations. Pregnancy at higher altitudes has distinctive physiologic attributes that affect perinatal outcomes and have been correlated with the duration and intensity of altitude. The effect of altitude on adult sleep has been studied at various elevations and has unique characteristics that may impact pregnant women. The effect of altitude on sleep during pregnancy is mostly unknown.

This dissertation research explored late pregnancy sleep quantity and quality characteristics at moderate altitude by comparing them to a similar sample at sea level, describing associations between moderate altitude sleep parameters and length of labor by self-report and medical records, and testing associations between sleep and pregnancy outcomes (length of labor and mode of delivery) at moderate altitude. Participants were nulliparous third trimester women (n=50) recruited in Flagstaff, Arizona (elevation 6910 feet [2106 meters]). A 3-day sleep diary and Pittsburgh Sleep Quality Index (PSQI) were completed between 35 gestational weeks and one week prior to delivery. Descriptive statistics, unpaired t-tests, Pearson product-moment correlation coefficients, ANCOVA, multiple regression, and logistic regression were utilized.

Results showed that after controlling for education, compared to nulliparous women at sea level, women at moderate altitude reported significantly higher sleep disturbance scores. After controlling for infant birth weight, length of labor was associated with the PSQI self-report measure for sleep onset latency. Together, infant birth weight, maternal weight, age, income, and sleep onset latency, hours of sleep, sleep disturbance, and sleep quality accounted for 51.6% of the variance in length of labor. Mode of delivery was also associated with sleep disturbance.