As so little is known about the causes of congenital heart disease, there's no guaranteed way of avoiding having a baby with the condition.
However, if you're pregnant, the following advice can help reduce the risk:
Ensure you are vaccinated against rubella and flu.
Avoid drinking alcohol or taking medication.
Take 400 micrograms of folic acid supplement a day during the first trimester (first 12 weeks) of your pregnancy – this lowers your risk of giving birth to a child with congenital heart disease, as well as several other types of birth defect.
Check with your GP or pharmacist before you take any medicine during pregnancy, including herbal remedies and medicine that's available over the counter.
Avoid contact with people who are known to have an infection.