Ventricular septal defect appears to run in families and sometimes occurs with other genetic problems, such as Down syndrome. If you already have a child with a heart defect, a genetic counselor can predict the approximate odds that your next child will have one.

Having the following conditions during pregnancy can increase your risk of having a baby with a heart defect.

  • Rubella infection. Becoming infected with German measles (rubella) while pregnant can increase the risk of fetal heart defects. The rubella virus crosses the placenta and spreads through the fetus' circulatory system damaging blood vessels and organs, including the heart.
  • Poorly controlled diabetes. Uncontrolled diabetes in the mother in turn affects the fetus' blood sugar, causing damaging effects to the developing fetus.
  • Drug or alcohol use or exposure to certain substances. Use of certain medications, alcohol or drugs or exposure to chemicals or radiation during pregnancy can harm the developing fetus.
Oct. 26, 2011

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