Cardiovascular disease in pregnancy is the most common cause of maternal mortality in the developed world and an important cause of heart failure, stroke, and arrhythmia. As more children with congenital heart disease survive into adulthood, there is a more pressing need to understand the risks that pregnancy poses for these women. Pregnancy, labor, and delivery increase the hemodynamic stress on the cardiovascular system and place women with heart disease at increased risk of cardiovascular complications, which include heart failure and death. Systematic assessment of pregnancy risk in these women, ideally before conception, is essential in optimizing maternal and fetal outcomes. This article describes the process of assessing risk of pregnancy-associated cardiovascular complications in women with structural heart disease. We review the current literature on pregnancy risk in women with complex congenital lesions, valvular heart disease, cardiomyopathy, and aortopathy, and suggest an approach to risk stratification. Based on a review of the literature, we report features that pose an increased risk of adverse maternal and fetal outcomes, which include poor maternal functional status; prior history of heart failure, arrhythmia, or cerebral vascular events; cyanosis; poor systemic ventricular function; and severe aortic or mitral stenosis. Pulmonary hypertension and Eisenmenger syndrome place women at exceedingly high risk for cardiovascular complications in pregnancy, including maternal and fetal death.