Objective - to measure poor sleep quality, its components, and the variables that contribute to it in a cohort of pregnant women across time. Four hundred and eighty-six strong singleton pregnancies were collected ahead of the fourteenth gestational week. Data on poor sleep quality were gathered before pregnancy and analyzed five distinct times in each trimester and six months after delivery. "Poor sleep quality (PSQ) was defined as a score of fewer than eight on the Athens Insomnia Scale (AIS), and for each trimester, adjusted odds ratios (aOR) with 95% confidence intervals (CI)"were acquired by use of multivariate logistic regression analysis. Pregnancy prevalence of poor SQ was 6.1 percent, followed by 44.2 percent in the first trimester (TR1), 46.3 percent in the second trimester (TR2), and 63.7 percent in the third trimester (TR3). Poor sleep quality after pregnancy was reported by 33.2 percent of women "(28.2-37.9) (p<0.001 for pre-gestational versus TR1, TR2 vs. TR3, and TR3 vs. post-pregnancy)."Due to a decrease in the quality of their nocturnal sleep, TR3's mean AIS score went from 2.34 before pregnant to 9.87; in contrast, TR1's detrimental impact on daytime functioning was larger. Poor sleep during the previous trimester was linked to poor sleep in TR2 and TR3. Poor SQ during pregnancy was a factor in TR1's poor SQ, and obesity was linked to bad sleep in TR3. The risks of having poor sleep quality in TR3 were instead decreased by moderate physical activity. Poor sleep throughout pregnancy was shown to be much more common than good sleep at any point in the pregnancy. In the latter stages of pregnancy, two out of every three expecting moms suffer poor SQ. Particular attention should be paid to pre-gestational poor SQ prevention and high body mass index.