A longitudinal study of prenatal marijuana use. Effects on sleep and arousal at age 3 years.

OBJECTIVE

To test the hypothesis that sleep disruptions would be evident in 3-year-old children with a history of prenatal marijuana exposure.

DESIGN

A prospective study using stratified random sampling beginning in the fourth month of pregnancy. Marijuana and other substance use were assessed by interviews at multiple time points. Offspring were followed up through age 3 years with multidomain assessments at fixed time points, including electroencephalographic sleep studies in the newborn period and at age 3 years.

SETTING

Primary care, prenatal clinic at a university hospital.

SUBJECTS

The sample included 18 children with prenatal marijuana exposure (mean [+/- SD] age, 39.0 +/- 4.4 months) and 20 control children (mean [+/- SD] age, 39.7 +/- 4.4 months). The two groups were similar in relationship to maternal age, race, income, education, or maternal use of alcohol, nicotine, and other substances in the first trimester.

MAIN OUTCOME MEASURE

Sleep variables from polysomnographic recordings at age 3 years.

RESULTS

Children with prenatal marijuana exposure showed more nocturnal arousals (mean [+/- SD], 8.2 +/- 5.3 vs 3.2 +/- 4.6; P < .003), more awake time after sleep onset (mean [+/- SD], 27.4 +/- 20.0 vs 13.7 +/- 12.4 min; P < .03), and lower sleep efficiency (mean [+/- SD], 91.0 +/- 3.8 vs 94.4 +/- 2.1; P < .03) than did control children.

CONCLUSION

Prenatal marijuana exposure was associated with disturbed nocturnal sleep at age 3 years.