A widely used illicit recreational drug among young adults, 3,4-methylenedioxymethamphetamine (MDMA) or ecstasy, is an indirect monoaminergic agonist/reuptake inhibitor affecting the serotonin system. Preclinical studies found prenatal exposure related to long-term learning and memory impairments. There are no studies of sequelae of prenatal MDMA exposure in humans, despite potential harmful effects to the fetus.
A total of 96 women in the United Kingdom (28 MDMA users; 68 non-MDMA) were interviewed about recreational drug use during pregnancy. Their infants were seen at 12 months using standardized assessments of cognitive, language, and motor development (Preschool Language Scale, Bayley Mental and Motor Development and Behavior Rating Scales [Mental Development Index, Psychomotor Development Index, Behavioral Rating Scale]). Mothers completed the Child Domain Scale of the Parenting Stress Index, The Home Observation of the Environment Scale (in interview), the Brief Symptom Inventory, and the Drug Abuse Screening Test. Women were primarily middle class with some university education, in stable partner relationships, and polydrug users. MDMA and other drug effects were assessed through multiple regression analyses controlling for confounding variables, and analysis of covariance comparing heavier versus lighter and nonexposed groups.
Amount of prenatal MDMA exposure predicted poorer infant mental and motor development at 12 months in a dose-dependent manner. Heavily exposed infants were delayed in motor development. Lighter-exposed infants were comparable to nonexposed infants. There were no effects on language, emotional regulation, or parenting stress.
Findings document persistent neurotoxic effects of heavier prenatal MDMA exposure on motor development through the first year of life.