The contents and recommendations published in the 2018 ESC guideline on heart diseases during pregnancy are supported by newer literature, so the dissemination of knowledge should be an integral part of cardiological specialist training. Expert opinions are in the foreground along with findings from clinical observational studies and registry data in a few randomized prospective studies. The continuous collection of data on cardiovascular diseases in pregnancy contributes significantly to the gain of knowledge. The number of women of childbearing age with pre-existing cardiovascular disease is increasing, and so is the need for advice and medical care for women wishing to have children and pregnant women with more complex cardiovascular diseases. This chapter provides a basic understanding of the most common pregnancy-associated cardiovascular diseases and contributes to the assessment of the risk of cardiovascular complications and the risk of death for the mother and the growing child.