The spectrum of cardiovascular disease affecting women in pregnancy and postpartum is changing and differs between countries. In the western world, the risk of cardiovascular disease in pregnancy has increased due to the increasing age at the first pregnancy and the worldwide obesity epidemic leading also to early diabetes and hypertension. In addition the treatment of congenital heart disease has improved leading to an increased number of women with residual heart disease reaching childbearing age. In the western world maternal heart disease is now the major cause of maternal death during pregnancy. In the developing world rheumatic heart disease and the cardiomyopathies dominate. Those women often need anticoagulation as they might have had a valve replacement or formed a thrombus in the left heart. Drugs during pregnancy and the breastfeeding period is a complex subject and there is a profound shortage of evidence based recommendations. As drug treatment in pregnancy concern the mother and the fetus optimum treatment of both must be targeted. This book aims at discussing the most important indications of drug usage in pregnancy and postpartum with the aim of weighing the potential risk of a drug and the possible benefit against each other.