Prenatal methamphetamine exposure and neonatal neurobehavioral outcome in the USA and New Zealand

BackgroundMethamphetamine (MA) use among pregnant women is a world-wide problem, but little is known of its impact on exposed infants.DesignThe prospective, controlled longitudinal Infant Development, Environment and Lifestyle (IDEAL) study of prenatal MA exposure from birth to 36 months was conducted in the US and NZ. The US cohort has 183 exposed and 196 comparison infants; the NZ cohort has 85 exposed and 95 comparison infants. Exposure was determined by self-report and meconium assay with alcohol, marijuana, and tobacco exposures present in both groups. The NICU Neurobehavior Scale (NNNS) was administered within 5 days of life. NNNS summary scores were analyzed for exposure including heavy exposure and frequency of use by trimester and dose–response relationship with the amphetamine analyte.ResultsMA exposure was associated with poorer quality of movement, more total stress/abstinence, physiological stress, and CNS stress with more nonoptimal reflexes in NZ but not in the USA. Heavy MA exposure was associated with lower arousal and excitability. First trimester MA use predicted more stress and third trimester use more lethargy and hypotonicity. Dose–response effects were observed between amphetamine concentration in meconium and CNS stress.ConclusionAcross cultures, prenatal MA exposure was associated with a similar neurobehavioral pattern of under arousal, low tone, poorer quality of movement and increased stress.