Effect of maternal smoking in pregnancy and childhood on child and adolescent sleep outcomes to 21 years: a birth cohort study.

Background: The effects of prenatal maternal smoking have been studied extensively, however little research has examined the effects of prenatal exposure to maternal smoking on offspring sleep, particularly over several developmental periods. We examined the effects of prenatal maternal smoking and postnatal smoking from birth to 14 years, on offspring sleep at 6 months, 5, 14 and 21 years.

Methods: This was a prospective, community-based birth cohort study involving 7223 women who delivered a singleton child in Brisbane, Australia between 1981 and 1983. Women were recruited at the first antenatal visit. Offspring sleep problems were reported by mothers at 6 months, 5 and 14 years, and by youth at 14 and 21 years. 3738 mothers prospectively reported their smoking status from pregnancy to 14 years postpartum. Youth snoring was reported by mothers at 14 years and by youth at 21 years. Multinomial logistic regression analyses were performed.

Results And Discussion: Prenatal maternal smoking was independently associated with an increased risk of offspring adolescent parasomnias including walking and talking in sleep and nightmares, and an increased likelihood of being in the highest quintile for maternal and youth reported sleep problems at 14 years. Maternal postnatal smoking was associated with increased likelihood of offspring snoring at 14 years.

Conclusions: Exposure to maternal prenatal smoking has different effects on offspring sleep compared to exposure to postnatal smoking. Prenatal smoking exposure may be associated with changes in neurodevelopment whereas postnatal smoking is more likely to affect the respiratory system. These findings highlight the long lasting and potentially serious clinical effects of exposure to pre and postnatal maternal smoking on offspring, the mechanisms by which warrant further investigation.