The primary objective of the National Pregnancy and Health Survey (NPHS) was to produce national annual estimates of the percentages and numbers of mothers of live newborns in the United States who used selected licit and illicit drugs in the 12 months prior to delivery. A further objective was to describe patterns of prenatal substance use among demographic subgroups of women. Information on demographic and socioeconomic characteristics, obstetric history, and drug treatment of women who delivered infants at sampled hospitals was obtained through an interviewer-administered questionnaire, while data on substance use before and during pregnancy were collected through a questionnaire completed by the respondent and concealed from the interviewer. Respondents were asked about use of the following substances: alcohol, amphetamines, analgesics, cocaine, crack cocaine, barbiturates, hallucinogens, hashish, heroin, marijuana, methadone, methamphetamine, sedatives, stimulants, tobacco, and tranquilizers. Additionally, information was collected on the respondent's pregnancy, prenatal care, delivery, previous pregnancies, and background. Additional data were obtained from the mothers' and infants' medical records. Urine specimens collected routinely by the hospital on obstetric admissions were tested for selected drugs. Finally, in a subsample of six hospitals, hair specimens were requested from respondents to evaluate the potential of hair as a source of toxicological data in future studies.This study has 1 Data Set.