Maternal night-time eating and sleep duration in relation to length of gestation and preterm birth

Maternal metabolic disturbance arising from inappropriate meal timing or sleep deprivation may disrupt circadian rhythm, potentially inducing pregnancy complications. We examined the associations of maternal night-time eating and sleep duration during pregnancy with gestation length and preterm birth.

We studied 673 pregnant women from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort. Maternal energy intake by time of day and nightly sleep duration were assessed at 26-28 weeks' gestation. Based on 24-h dietary recall, night-eating was defined as consuming >50% of total energy intake from 1900 to 0659 h. Short sleep duration was defined as <6 h night sleep. Night-eating and short sleep were simultaneously analyzed to examine for associations with a) gestation length using multiple linear regression, and b) preterm birth (<37 weeks' gestation) using logistic regression.

Overall, 15.6% women engaged in night-eating, 12.3% had short sleep and 6.8% delivered preterm. Adjusting for confounding factors, night-eating was associated with 0.45 weeks shortening of gestation length (95% CI -0.75, -0.16) and 2.19-fold higher odds of delivering preterm (1.01, 4.72). Short sleep was associated with 0.33 weeks shortening of gestation length (-0.66, -0.01), but its association with preterm birth did not reach statistical significance (1.81; 0.76, 4.30).

During pregnancy, women with higher energy consumption at night than during the day had shorter gestation and greater likelihood of delivering preterm. Misalignment of eating time with day-night cycles may be a contributing factor to preterm birth. This points to a potential target for intervention to reduce the risk of preterm birth. Observations for nightly sleep deprivation in relation to gestation length and PTB warrant further confirmation.