OBJECTIVE Systemic sclerosis, primary pulmonary hypertension, and sickle cell disease are uncommon vasculopathic diseases affecting women. We estimated the nationwide occurrence of pregnancies in women with these conditions and compared pregnancy outcomes to the general obstetric population. METHODS We studied the 2002-2004 Nationwide Inpatient Sample, of the Healthcare Cost and Utilization Project to estimate the number of obstetric hospitalizations and deliveries among women with systemic sclerosis, primary pulmonary hypertension, sickle cell disease, and women in the general population. Pregnancy outcomes included length of hospital stay, hypertensive disorders including preeclampsia, intrauterine growth restriction (IUGR), and cesarean delivery. Multivariable regression analyses were performed using maternal age, race or ethnicity, antiphospholipid antibody syndrome, diabetes mellitus, and renal failure as covariates. RESULTS Of an estimated 11.2 million deliveries, 504 occurred in women with systemic sclerosis, 182 with primary pulmonary hypertension, and 4,352 with sickle cell disease. Systemic sclerosis, was associated with an increased risk of hypertensive disorders including preeclampsia (odds ratio [OR] 3.71, 95% confidence interval [CI] 2.25-6.15), IUGR (OR 3.74, 95% CI 1.51-9.28), and increased length of hospital stay. Primary pulmonary hypertension was associated with an increase in the odds of antenatal hospitalization (OR 4.67, 95% CI 2.88-7.57), hypertensive disorders including preeclampsia (OR 5.62, 95% CI 2.60-12.15) and a substantial increase in length of hospital stay. Sickle cell disease was associated with an increased odds of antenatal hospitalization (OR 5.56 95% CI 5.08-6.09), hypertensive disorders including preeclampsia (OR 1.78, 95% CI 1.48-2.14), and IUGR (OR 2.91, 95% CI 2.16-3.93), with a modest increase in length of hospital stay. CONCLUSIONS Women with systemic sclerosis, primary pulmonary hypertension, and sickle cell disease have significantly increased rates of adverse pregnancy outcomes, requiring extensive preconceptional counseling about the risks of pregnancy.