Statistical analyses
Baseline characteristics were presented as mean ± standard deviation (SD) or median (interquartile range) for continuous variables, and n (%) for categorical variables. T tests, Mann-Whitney Utests and χ2 tests were used to analyze the relationships of basic characteristics between birth outcome categories. Multivariable logistic regression was used to examine the relationship between sleep and birth outcomes. Odds ratios (ORs) and their 95% confidence intervals (95% CIs) were calculated in a stepwise manner. In Model 1: unadjusted. In Model 2: age, employment, education, place of residence, and family income, smoking, drinking, physical activity in the first trimester, physical activity in the second trimester, parity, pre-pregnancy BMI, GWG, sleep quality and changes in sleep quality during pregnancy were adjusted. In Model 3: Based on Model 2, preeclampsia, HDP and GDM were further adjusted. Statistical analyses were conducted by SPSS software version 26 with two-sided Pvalues <0.05 as the level of significance.