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Genetic Testing (Twins)

WebMD Medical Reference
Reviewed by Nivin Todd, MD

Who Gets the Test?

Genetic testing is an option for any woman before or during pregnancy. Sometimes the babies' father gets tested, too. Your doctor may suggest genetic testing if family history puts your babies at a higher risk of inherited diseases.

The tests you need may depend on your heritage. Certain ethnic groups have a higher risk of certain diseases. For instance, people with eastern European or Ashkenazi backgrounds have a higher risk of Tay-Sachs disease and Canavan disease. African-Americans have a higher risk of sickle cell disease. Caucasians have a higher risk of cystic fibrosis.

What the Test Does

Doctors use different types of genetic testing. Standard screenings check your babies' risk of birth defects such as Down syndrome, trisomy 18, trisomy 13, neural tube defects, and others. Carrier tests can show if you -- or the babies' father -- could carry genetic diseases. These include cystic fibrosis, Fragile X syndrome, sickle cell disease, Tay-Sachs, and others.

How the Test Is Done

A nurse or phlebotomist will take a sample of your blood or saliva. There is no risk to you or your babies.

What to Know About the Test Results

Genetic tests don't diagnose your babies with a disease. They only tell you if your babies have a higher risk. Your doctor may suggest follow-up tests, such as amniocentesis or CVS, to get more information.

Testing the father can also help. Some diseases can be inherited only if both parents carry the gene. Your doctor can rule out some problems, such as Tay-Sachs, cystic fibrosis, and sickle cell anemia, if the father tests negative -- even if you test positive.

How Often the Test Is Done in Your Pregnancy

Just once.

Other Names for This Test

Carrier Screening, Triple Screen, Quad Screen, Multiple Marker Screening

Tests Similar to This One

Amniocentesis, CVS

Reviewed on May 23, 2014

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