Association Between Sleep Quality and Duration During Pregnancy and Risk of Infant Being Small for Gestational Age: Prospective Birth Cohort Study.

Background: Maternal sleep disturbance is a risk factor for adverse outcomes like preterm birth. However, the association of maternal sleep quality and duration with the risk of the infant being small for gestational age (SGA) remains inconclusive, and the specific critical window of vulnerability has yet to be clearly identified. Therefore, this study aims to investigate the effect of maternal sleep quality and duration on the risk of having an SGA infant and to identify the critical window for this association.

Methods: One thousand six hundred and seventy-seven participants from the Shenzhen Birth Cohort Study were included. Maternal sleep duration and quality during pregnancy were assessed using the Pittsburgh Sleep Quality Index (PSQI) in early (<19 weeks), mid- (24-28 weeks), and late (32-38 weeks) pregnancy. Multivariate logistic regression analyses were used to examine the association of an SGA infant with sleep duration and quality, along with their specific effects across the different pregnancy stages.

Results: The pregnant women with short sleep duration (≤7 h/day) in the early stage of pregnancy appeared to have a higher risk of having an SGA infant (aOR = 1.93, 95% CI = 1.32~2.79). Additionally, poor sleep quality combined with short sleep duration was associated with an even higher risk of having an SGA infant (aOR = 2.08, 95% CI = 1.32~3.23). However, this association was observed only during early pregnancy.

Conclusions: The women with short sleep duration were associated with SGA risk, and the early stage of pregnancy might be a particularly sensitive period for this relationship. Addressing maternal sleep problems during pregnancy as part of antenatal care is crucial for reducing the likelihood of having an SGA infant and improving the overall birth outcomes.