Cannabis Use During Pregnancy

Marijuana is the most commonly used drug of abuse during pregnancy in the United States,1 with self-reported use ranging from 2–5% for all women and 15–28% among women who are young, urban, and socioeconomically disadvantaged.2 Many patients use it for its nausea-relieving properties during pregnancy and believe it is relatively safe since it is natural.

The reality is the more than 500 chemicals found in marijuana — including the mind-altering compound delta-9-tetrahydrocannabinol (THC) — can pass through a woman's placenta to the developing fetus during pregnancy and to a baby through breast milk, affecting the growing infant.1 While data is limited and often confounded by other substance use, research indicates a significant risk of cannabis use in pregnancy.3 Reviews show infants born to women who used marijuana during pregnancy were more likely to require neonatal intensive care unit admission, had lower birth weights,4 higher stillbirth rates, and lower Apgar scores (i.e., a test after birth to determine how well the baby tolerated the birthing process).5

Analyses of longitudinal studies show associations between prenatal marijuana exposure and developmental effects on adolescents, including decreased performance on memory, impulse control, problem-solving, quantitative reasoning, verbal development, and visual analysis tests.6 Many effects persist into young adulthood and appear to have a dose-dependent relationship.7

This educational supplement describes different cannabis products, their effects, practice guidelines and recommendations, and screening tools to identify patients who are using cannabis during pregnancy and while breastfeeding.