What causes congenital cardiovascular defects?
Congenital cardiovascular defects are present in about 1 percent of live births. They’re the most common congenital malformations in newborns. In most cases scientists don’t know why they occur. Sometimes a viral infection causes serious problems. German measles (rubella) is an example. If a woman contracts German measles while pregnant, it can interfere with how her baby’s heart develops or produce other malformations. Other viral diseases also may cause congenital defects. Heredity sometimes plays a role in congenital cardiovascular defects. More than one child in a family may have a congenital cardiovascular defect, but this rarely occurs. Certain conditions affecting multiple organs, such as Down’s syndrome, can involve the heart, too. Some prescription drugs and over-the-counter medicines, as well as alcohol and “street” drugs, may increase the risk of having a baby with a heart defect. Researchers are studying other factors.
