Objectives: To survey the effects of pregnancy on mothers' sleep.
Methods: Mothers were interviewed during and after pregnancy with a series of five questionnaires to assess alterations in their sleep. The first questionnaire covered the 3 months before becoming pregnant, the next three the trimesters of pregnancy and the last the 3 months after delivery. The study was carried out in a central hospital and the maternity care units in the nearby rural community. Altogether, 325 pregnant women completed all five questionnaires.
Results: The total amounts of reported sleep and of nocturnal sleep increased significantly during the first trimester of pregnancy, began to decrease thereafter and were shortest during the 3 months after pregnancy. During late pregnancy expectant mothers over 30 years of age reported less sleep than those under 30. During the whole pregnancy, but increasingly toward the end of pregnancy, sleep became more restless and fragmentary and its subjective quality worsened, due at least partly to increased restless legs and nightly awakenings increasing with advancing pregnancy.
Conclusions: The subjective quality of sleep is disturbed as early as the first trimester of pregnancy, although total sleeping time increases. The amount of reported sleep begins to decrease in the second trimester. The frequency of reported sleep disturbances, such as restless legs syndrome and nocturnal awakenings, is maximum in the third trimester but is about normal within 3 months after delivery.