Physicians who treat pregnant women (see  Chap. 82) should be aware of the effects of known teratogens as well as drugs (e.g., angiotensin-converting enzyme [ACE] inhibition and fetal renal development) that may have a functional rather than a structural damaging influence on the fetal and newborn heart and circulation. They should also recognize that for many drugs, information about their teratogenic potential is inadequate. Similarly, appropriate radiologic equipment and techniques for reducing gonadal and fetal radiation exposure should always be used to reduce the hazards of this potential cause of birth defects.

Detection of genetic abnormalities during fetal life is becoming an increasing reality. Fetal cells are obtained from amniotic fluid or chorionic villus biopsy. Many fetuses in whom CHD is detected will undergo genetic testing, and fetal echocardiography is frequently indicated when a chromosomal abnormality is diagnosed for other reasons. Many social, religious, …