Objectives: To describe different sleep disorders and daytime sleepiness in a French population of randomly selected young women during pregnancy and to evaluate the frequency of these sleep disorders according to the three trimesters of pregnancy. Methods: Cross-sectional design with retrospective survey of pre-pregnancy, symptoms and prospective survey of current symptoms. Mothers were interviewed during pregnancy with a questionnaire to evaluate their sleep before pregnancy and to assess alterations in their sleep according to the trimester. Results: 871 pregnant women completed the questionnaire. The rate of pregnant women with insomnia with non-refreshing sleep and frequent awakenings increases during the second and the third trimester reaching more than 75% of the women, essentially due to an urge to urinate, movements of the fetus, backache and restless legs syndrome. Snoring also increases throughout the pregnancy with more than 18% of them snoring every night. Conversely, more than 75% of the women complained of a decrease in their vigilance and a need to nap inreased during the pregnancy. Conclusions: The subjective quality of sleep is disturbed as early as the first trimester of pregnancy and increases throughout the pregnancy, except for excessive daytime sleepiness which was more frequent during the first trimester.