The decision to have the test is personal. You must think about your chance of passing on a family disease, your age, your need to know about any problems, and what you might do once you have the test results. Your spiritual beliefs and other values also may play a role in your decision.

Some birth defects-such as a cleft lip or cleft palate or certain heart problems-can be fixed with surgery after birth and sometimes even surgery during pregnancy. Other defects, such as mental retardation, cannot be fixed.

You may decide to have the tests because:

• You would think about whether to continue the pregnancy if there is a birth defect.
• You have a family history of an illness such as cystic fibrosis, Tay-Sachs disease, or hemophilia. For more information on cystic fibrosis testing, see the topic Cystic Fibrosis Carrier Screening.
• You are age 35 or older or will be on your due date; this increases your chance of having a child with Down syndrome.
• You need to know whether there might be a problem; not knowing would make you worry.
• You want to learn all you can about caring for and raising a child with a certain birth defect.
• You have insurance that will pay for some or all of the cost of the tests.