The existing research on pregnancy outcomes for women with intellectual and developmental disabilities (IDD) is sparse. This study analyzed the 2010 Healthcare Cost and Utilization Project Nationwide Inpatient Sample and compared deliveries among women with IDD (n = 340) to the general obstetric population. Women with IDD had longer hospital stays and were more likely to have Caesarean deliveries in contrast to other women. Rates of adverse pregnancy outcomes were elevated for women with IDD across a range of measures, including early labor, preterm birth, and preeclampsia, and their infants were more likely to have low birth weight, even after adjusting for age, race, ethnicity, and insurance type. Targeted interventions are needed to address these deleterious outcomes.