Associations of Maternal Sleep Quality Trajectories During Pregnancy and Preterm Birth: A Prospective Cohort Study

Little is known about the relationship between sleep quality trajectories during pregnancy and preterm birth. To address this issue, we conducted a longitudinal assessment of maternal sleep quality to examine the relationship between sleep quality trajectories across all trimesters and the risk of preterm birth. A prospective birth cohort study was conducted in China, and a total of 15,042 women who had singleton births were included, including 647 who subsequently developed preterm birth. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI) scale at each study visit (8-14, 22-27 and 32-37 weeks of gestation). Preterm birth was defined as birth less than 37 weeks of gestation. Latent class trajectory models were applied to identify different sleep quality trajectories, and multivariate logistic regression models were applied to examine the associations between the determined trajectories and preterm birth. This study identified three distinct sleep quality trajectories: stable good group, stable poor group and increasing poor group. After adjusting for covariates, the odds ratio for preterm birth in the increasing poor group was 1.32 (95% confidence interval: 1.05-1.66) compared to the stable good group. Positive associations of the increasing poor group with preterm birth were exhibited only among women aged less than 30 years, those with normal BMI, or mothers of female infants. Our findings revealed that an increasing poor sleep quality trajectory was associated with an increased risk of preterm birth and emphasised the imperative to identify the high-risk groups as a priority target for intervention and treatment.