Subjective and objective assessment of sleep quality during each trimester of pregnancy: a prospective observational study

Abstract Background Sleep disturbances due to hormonal imbalance are common during pregnancy. Studies have suggested that poor sleep quality in pregnant women can lead to perinatal abnormalities; therefore, the need of the hour is to determine the actual circumstances of sleep during pregnancy from an early stage, and provide support for better sleep quality. Therefore, the present study aimed to assess sleep quality by objective assessment using an actigraph and subjective assessment using a questionnaire for sleep during each trimester of pregnancy, and to elucidate how sleep quality changed from the first to the third trimester of pregnancy. Methods A longitudinal questionnaire survey and sleep measurements using actigraph were conducted at three time points, during the first, second, and third trimester, of pregnancy for primiparous women who had conceived naturally. Results During the first trimester of pregnancy, there was no “feeling of being refreshed when waking up in the morning,” and there was a decline in mental function. During the second trimester of pregnancy, a positive correlation between morning sickness and sleep quality (r = 0.59, p = 0.001) was observed. Sleep quality was the worst during the third trimester, with the shortest total sleep time (382.6 ± 26.3 min, F = 11.7, p = 0.0001) and poor sleep efficiency (93.9%±3.2%, F = 4.1, p = 0.0029). Physical function score was also poor. Regarding minor troubles that affected sleep efficiency, back pain (r = 0.47, p = 0.03) and leg cramps (r = 0.57, p = 0.01) exhibited significant correlation with sleep efficiency in the third trimester of pregnancy. Conclusions Poor sleep during pregnancy begins from the first trimester; if minor troubles such as morning sickness continue in the second trimester, sleep quality is greatly affected. Furthermore, during the third trimester of pregnancy, low back pain and leg cramps are more likely to occur due to the increase in the abdominal area, and may interfere with sleep.