Sleep Disturbances in Pregnancy

Abstract

A number of studies have reported associations between sleep disorders and adverse outcomes in both elderly and younger populations, but because few included pregnant women it is unclear whether sleep abnormalities during pregnancy are associated with adverse health consequences. Previous reports on sleep and pregnancy have focused only on specific sleep disturbances such as snoring, and most have studied a very heterogeneous population and included women with preexisting medical conditions. Few investigators have evaluated changes in sleep disturbances across pregnancy, or in women without chronic medical conditions that could independently affect sleep. This prospective observational study evaluated the prevalence of sleep disturbances among a population of healthy nulliparous women and quantified changes in sleep during pregnancy. Between February 2007 and June 2008, a total of 189 study subjects completed a sleep survey questionnaire at baseline early in pregnancy at 6 to 20 weeks and again in the third trimester at 28 to 40 weeks. The questionnaire was self-administered and contained items from several validated sleep surveys including the Berlin Questionnaire for Sleep-Disordered Breathing, the Epworth Sleepiness Scale, the National Institutes of Health/International Restless Legs Syndrome Question Set, the Women's Health Initiative Insomnia Rating Scale, and the Pittsburgh Sleep Quality Index. Overall changes in sleep characteristics between the baseline and third-trimester surveys were estimated through the use of the paired t-test for continuous variables and the McNemar test for categorical data. The mean gestational age of the participants at the first and second surveys was 13.8 ± 3.8 and 30.0 ± 2.2 weeks. The data showed that mean sleep duration was shortened from 7.4 ± 1.2 hours in the initial survey to 7.1 ± 1.3 in the third trimester survey (P < 0.001). Compared to baseline assessment, the percentage of patients with frequent snoring (at least 3 nights per week) was significantly increased in the third trimester (11.1% vs. 16.4%, P = 0.03). The proportion of women with test results positive for restless leg syndrome increased from 17.5% to 31.2% (P = 0.001). In addition, the overall poor sleep quality defined as a Pittsburgh Sleep Quality Index score above 5 was more common in the third trimester (39.0% vs. 53.5% (P = 0.001). These findings show that sleep disturbances are common in healthy nulliparous pregnant women, especially in the third trimester.