In the Infant Development, Environment and Lifestyle (IDEAL) Study of methamphetamine (MA) effects on children, the authors screened approximately 27,000 newborn infants for MA exposure, and from that pool derived a sample of in utero MA-exposed children as well as a comparison group matched for other drug use and other factors. IDEAL measures cognition, social relationships, neuromotor development, neuroendocrine function, and general health. Preliminary analyses from the neonatal period have yielded findings in several areas: (1) Pregnant users and nonusers of MA did not differ in race, age, education, type of insurance, current partner status, or religious preference. After adjusting for alcohol, tobacco, marijuana, and SES, no differences were found in total depression and psychiatric symptom scores between the two groups. (2) MA-exposed newborns had lower birth weight and were 4.5 times more likely to be small for gestational age than babies born to non-MA users. (3) MA use during the first trimester was related to more signs of stress in infants. Use in the second trimester was associated with more lethargy. Use in the third trimester was related to poorer quality of movement and greater physiological stress. (4) Authors recommend providing MA-involved families with parenting support, medical support, and mental health care.