Congenital heart disease in pregnancy.

Congenital heart disease is now more prevalent than acquired in pregnancy in the developed world. In pregnancy the fall in systemic vascular resistance and increase in blood volume and cardiac output can cause functional deterioration in certain conditions. A minimally symptomatic woman with good ventricular function, normal oxygen saturation, and no left heart obstruction should tolerate pregnancy well. Women with pulmonary hypertension or dilated aortic root (pre-replacement) should be counselled against pregnancy and given appropriate contraceptive advice. The optimum management of a pregnant woman with a metallic prosthetic valve remains to be determined.