MDMA (Ecstasy) use during pregnancy is linked to poorer motor quality and lower milestone attainment in infants at 4 months, with a dose-response relationship: greater exposure corresponds to worse motor outcomes. This first prospective study of prenatal MDMA exposure in humans compared 28 women who used MDMA during pregnancy with 68 polydrug-using women who did not, controlling for confounding factors. MDMA-using mothers had fewer prior births and more health, work, and social problems. Exposed infants were more likely to be male. The findings suggest risk to the developing infant and indicate that continued follow-up is needed to determine whether early motor delays persist or resolve.
Heavier prenatal exposure to MDMA (ecstasy) predicted poorer mental and motor development in 12-month-old infants, with motor delays appearing in a dose-dependent manner. Lighter-exposed infants were comparable to nonexposed infants. No effects were found on language, emotional regulation, or parenting stress. The study involved 96 women in the United Kingdom—28 who used MDMA during pregnancy and 68 who did not—and used standardized developmental assessments.