Prenatal Cannabis Exposure Tied to Adverse Childhood Sleep Outcomes

By Lisa Rappaport

July 20, 2020

(Reuters Health) - Prenatal cannabis exposure is associated with a variety of sleep disorders among children 9-10 years old including issues with sleep duration, initiating and maintaining sleep, and excessive somnolence, a recent study finds.

Researchers examined data on sleep outcomes for 11,875 children aged 9-10 years and also examined a variety of health and socioeconomic data on their mothers, including 695 mothers (6%) who reported cannabis use during pregnancy.

In adjusted analysis accounting for socioeconomic status and other prenatal substance use, children with any prenatal cannabis exposure were more likely to have issues with sleep duration (effect size 0.08), initiating and maintaining sleep (effect size 0.14), arousal (effect size 0.10), sleep-wake disorders (effect size 0.16), and excessive somnolence (effect size 0.11) than children without prenatal cannabis exposure.

Daily frequency of cannabis use was also associated in adjusted analysis with with sleep duration issues (effect size 0.22), and excessive somnolence (effect size 0.29).

These results offer fresh evidence that women should abstain from cannabis use while pregnant, the study team concludes in Sleep Health.

"The fetal brain is densely populated with cannabinoid receptor type 1 (CB1) receptors that increase in activity throughout gestation and are thought to influence brain development," said study co-author Evan Winiger of the Institute for Behavioral Genetics at the University of Colorado Boulder.

CB1 receptors might be involved in the modulation and regulation of sleep processes, since they can be found in many brain areas related to the regulation of the sleep-wake cycle such as the hypothalamus, cerebellum, and basal forebrain, Winiger said by email.

"THC binds to CB1 receptors, and animal models suggest this possibly alters neurodevelopment and fetal cortical circuitry in the womb," Winiger said.

The study controlled for covariates that included prenatal substance exposure, mother's education, combined household income, parental marital status, race, child sex, and child age, the authors note.

Limitations include the potential for bias against reporting substance use while pregnant, poor recollection of the frequency of any cannabis use during pregnancy, and potential errors in parent-reported sleep measures for children.

In addition, even though the study controlled for many factors, it didn't address anything that happened to children in the years between birth and ages 9-10 that might negatively impact sleep, said Deborah Hasin, a professor of epidemiology in psychiatry at Columbia University Irving Medical Center in New York City.

"For example, poor parenting or adverse childhood experiences (ACE) could have had a greater impact on sleep and other aspects of functioning at ages 9-10 than prenatal cannabis exposure, and both poor parenting and/or exposure to ACE could be related to cannabis use during pregnancy by the mother," Hasin, who wasn't involved in the study, said by email.

However, it's possible that a study that included information on exposure to poor parenting or ACE would still show that prenatal exposure to cannabis predicts poor sleep at ages 9-10, Hasin said.

"For this reason, for now, the cautious clinical advice would be not to use cannabis during pregnancy or while trying to conceive," Hasin said.

SOURCE: Sleep Health, online June 28, 2020.