ACOG: Doctors Should Urge Against Prenatal Marijuana Use

Studies show that children exposed to marijuana in utero have lower scores on tests of visual problem-solving, visual and motor coordination, and visual analysis, compared with children not exposed to the drug, the report states. Prenatal marijuana exposure also has been associated with decreased attention span and behavioral problems. The nervous system of a human fetus can respond to the chemicals in marijuana within 14 weeks of gestation, and studies have shown that 14-year-olds are more likely to be marijuana users if their mothers used the drug during pregnancy.