CONTEXT:Prenatal care generally includes contraceptive and health education that may help women to control their subsequent fertility. However, research has not examined whether receipt of prenatal care is associated with subsequent birthspacing.

METHODS:Longitudinally linked birth records from 113,662 New Jersey women who had had a first birth in 1996–2000 were used to examine associations between the timing and adequacy of prenatal care prior to a woman’s first birth and the timing of her second birth. Multinomial logistic regression analyses adjusted for social and demographic characteristics, hospital and year of birth.

RESULTS:Most women (85%) had initiated prenatal care during the first trimester. Women who had not obtained prenatal care until the second or third trimester, or at all, were more likely than those who had had first-trimester care to have a second child within 18 months, rather than in 18–59 months (odds ratios, 1.2–1.6). Similarly, women whose care had been inadequate were more likely than those who had had adequate care to have a short subsequent birth interval (1.2). The associations were robust to alternative measures of prenatal care and birth intervals, and were strongest for mothers with less than 16 years of education.

CONCLUSIONS:Providers should capitalize on their limited encounters with mothers who initiate prenatal care late or use it sporadically to ensure that these women receive information about family planning.