Longitudinal associations between sleepiness and sleep disturbances across pregnancy

Although sleep disturbances increase during pregnancy, sleepiness does not appear to follow a similar trajectory. Given that the relationship between sleep disturbances and sleepiness during pregnancy is understudied, we examined their associations to determine whether these relationships strengthen with advancing gestation.

For this prospective longitudinal survey, we enrolled 3808 women, of whom 3286 responded. Sleep disturbances were assessed in early pregnancy, midpregnancy, and late pregnancy and at delivery. Mixed-effects models were constructed with adjustments for age, body mass index, parity, maternal smoking, and depressive symptoms.

Sleepiness decreased from early to midpregnancy and increased thereafter, being highest at delivery. In contrast, the proportion of women with insomnia increased from 19.1% in early pregnancy to 59.1% at delivery. The proportion of habitual snorers (three or more times per week) and short sleepers (<7 h per night) increased as pregnancy progressed, whereas the proportion of long sleepers (>9 h per night) remained stable. Significant sleep loss (>2 h) increased particularly at delivery. Greater sleepiness was consistently associated with insomnia symptoms (all P < 0.001), with stronger effect size estimates in late pregnancy. Sleepiness was also associated with habitual snoring from midpregnancy onwards. Short sleep duration and sleep loss were related to greater sleepiness throughout pregnancy (all P < 0.001), but long sleep duration was associated with greater sleepiness only in early pregnancy.

Sleepiness during pregnancy followed a U-shaped trajectory but was consistently associated with insomnia, short sleep duration, sleep loss, and snoring from midpregnancy onwards. Screening for underlying sleep disturbances among pregnant women reporting sleepiness may provide an opportunity for timely identification and management, potentially improving maternal well-being.