Objective To examine the association of pregnancy and parenting (0- to 2-year-old child) statuses with past 30-day use of alcohol, cigarettes and marijuana, psychotherapeutics and cocaine among American women aged 18–44, overall and by race/ethnicity. Methods Five years of data (2002–2006) from the National Survey on Drug Use and Health (NSDUH) were pooled. Binary logistic regression analyses stratified by race/ethnicity were performed to examine the relationships adjusting for age, marital status, education and family income. Results Overall, past 30-day alcohol, cigarette, marijuana, psychotherapeutic or cocaine use was substantially lower among pregnant women, particularly in their second or third trimesters, than among their parenting or non-pregnant counterparts. Logistic regression analysis suggested a strong negative association between pregnancy status and substance use, with no considerable variations in the magnitude of the relationship by race/ethnicity for most measures. The relationship between parenting status and substance use was in the same direction, but relatively weak, and not statistically significant for non-Hispanic (NH) blacks for any measures except for alcohol use. Regardless of pregnancy and parenting statuses, NH white women reported substance use at the highest rates, followed by Hispanics and NH blacks. Conclusions There is indirect evidence of postpregnancy resumption in substance use. Pregnant and parenting women, regardless of race/ethnicity, could benefit from prevention efforts focusing on cessation rather than temporary abstinence from substance use.