It's not known why atrial septal defects occur, but congenital heart defects appear to run in families and sometimes occur with other genetic problems, such as Down syndrome. If you have a heart defect, or you have a child with a heart defect, a genetic counselor can estimate the odds that any future children will have one.

Some conditions that you have or that occur during pregnancy may increase your risk of having a baby with a heart defect, including:

  • Rubella infection. Becoming infected with rubella (German measles) during the first few months of your pregnancy can increase the risk of fetal heart defects.
  • Drug, tobacco or alcohol use, or exposure to certain substances. Use of certain medications, tobacco, alcohol or drugs, such as cocaine, during pregnancy can harm the developing fetus.
  • Diabetes or lupus. If you have diabetes or lupus, you may be more likely to have a baby with a heart defect.
  • Obesity. Being extremely overweight (obese) may play a role in increasing the risk of having a baby with a birth defect.
  • Phenylketonuria (PKU). If you have PKU and aren't following your PKU meal plan, you may be more likely to have a baby with a heart defect.
Dec. 11, 2014

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