Maternal sleep duration and neonate birth weight: A population-based cohort study

Int J Gynaecol Obstet. 2022 Mar;156(3):494-501. doi: 10.1002/ijgo.13685. Epub 2021 Apr 19.


Objective: To investigate the association between maternal sleep duration (an important health indicator) and neonate birth weight.

Methods: The study included 2536 mother-neonate pairs of a Spanish birth cohort (2004-2006, INMA project). The exposures were questionnaire-based measures of sleep duration before and during pregnancy. The primary outcome was neonate birth weight score (g) standardized to 40 weeks of gestation.

Results: In women sleeping for <7 h/day before pregnancy, each additional hour of sleep increased birth weight score by 44.7 g (P = 0.049) in the minimally adjusted model, although findings were not statistically significant after considering other potential confounders (P > 0.05). However, increasing sleep duration for the group of mothers who slept for more than 9 h/day decreased birth weight score by 39.2 g per additional hour (P = 0.001). Findings were similar after adjusting for several sociodemographic confounders and maternal depression-anxiety clinical history as an intermediate factor. Similar but attenuated associations were observed with sleep duration in the second trimester of pregnancy.

Conclusion: The relationship between maternal sleep duration before and during pregnancy and neonate birth weight is an inverse U-shaped curve. Excessive sleep duration may adversely affect neonate health through its impact on birth weight.

Keywords: birth outcomes; birth weight; maternal health; population-based birth cohort; sleep duration.

MeSH terms

  • Birth Weight
  • Cohort Studies
  • Female
  • Humans
  • Infant, Newborn
  • Mothers*
  • Pregnancy
  • Pregnancy Trimester, Second
  • Sleep*

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