What is prenatal genetic testing, and should I get it?

Genetic tests can help you and your providers make informed decisions about your pregnancy.

With many advancements in medicine, you can learn so much about the health of your baby. That’s why when you’re pregnant, you can expect to have many screening tests to check for risks of birth defects and other issues in your growing baby.

And you probably think genetic testing is included in these screenings — but it’s actually not required. The decision to have genetic testing on your baby is entirely up to you and your family.

“While genetic testing is optional, results of these tests can be helpful for families and providers to make informed decisions about your pregnancy,” said Michael Krew, MD, director of Maternal-Fetal Medicine at Akron Children’s. “If a disorder is found, providers can diagnose conditions before your baby is born. Together, you and your provider can start planning for your baby’s care.”

But not all families decide to have genetic testing for various reasons. Talk to your doctor about what’s right for you and your baby. Your provider can discuss with you the benefits and risks of all the genetic tests and what’s involved to help your family make an informed decision.

What is prenatal genetic testing?

Genetic tests look for congenital conditions or birth defects like Down syndrome, cystic fibrosis, sickle cell disease, trisomy 13 (Patau syndrome), Turner syndrome and spina bifida. Some conditions are passed down through families, but not all of them.

There are 2 types of prenatal genetic testing: screening and diagnostic tests. Screening tests determine whether your baby is more likely to have a genetic condition. Diagnostic ones can do just that: diagnose a condition.

Screening genetic tests

Screening tests check for risks of genetic problems but don’t diagnose them. Some common genetic screening tests include:

• Carrier screening: A blood test that can identify small changes in the genes that show you could be a carrier for a genetic risk, such as cystic fibrosis, sickle cell disease and spinal muscular atrophy. For most of these conditions, a baby is only at risk when both parents are carriers for the same condition.
• NIPT (noninvasive prenatal testing): Performed after 10 weeks of pregnancy, a blood test where providers can look for abnormal chromosomes (either missing or extra ones) in your baby’s DNA.
• Nuchal translucency: Performed between 11 and 14 weeks of pregnancy, ultrasound is used to measure the thickness of the back of your baby’s neck. A thicker nuchal translucency can mean a higher risk for abnormal chromosomes.
• Anatomy scan: Performed between 18 and 20 weeks of pregnancy, ultrasound is used to examine baby from head to toe. If development problems in organs and body parts are found, it can mean a baby has a higher chance of a birth defect or genetic condition.

“Abnormal results can mean your baby has a higher chance of having a specific condition — but it doesn’t mean your baby has the birth defect,” said Dr. Krew. “It means your doctor will want to further evaluate to learn more.”

Your provider or genetic counselor will help you understand these results and what they mean. Together, you can decide on next steps.

Diagnostic genetic tests

If your screening test came back abnormal or if your baby is at a higher risk of a genetic condition, your provider may refer you to a maternal-fetal medicine specialist for diagnostic genetic testing. These tests can confirm if your baby has a genetic condition.

• Chorionic villus sampling (CVS): Performed between 10 and 13 weeks of pregnancy, a provider inserts a thin needle into your uterus using ultrasound guidance to remove a small sampling of cells from the placenta for a lab analysis. It also can be done through the vagina.
• Amniocentesis: Performed between 16 and 20 weeks of pregnancy, a provider inserts a thin needle through your skin into your uterus using ultrasound guidance to remove amniotic fluid for a lab analysis.

It can take a few weeks to receive results. When you do, genetic counselors are available to explain the results, help you navigate a diagnosis and offer information about your baby’s condition and support for your family.

Genetic counselors can help you decide if testing is right for you.

Who should get prenatal genetic testing?

It’s a personal choice whether to get genetic testing, based on your medical history or personal beliefs. But your provider may recommend genetic testing during pregnancy if you:

• Had an abnormal result from an ultrasound or blood test screening
• Have a personal or family history of genetic conditions
• Are over age 35
• Have had a miscarriage or stillbirth before

Ultimately, the decision is up to you. Weighing the pros and cons of genetic testing can help you decide whether to move forward. It’s also a good idea to think about why you want to be tested and what you’ll do with that information after getting the results.

Are there risks of genetic testing?

Because most genetic screenings are blood tests or ultrasounds, there is no risk to you and your baby. However, genetic diagnostic tests do come with increased risks, such as bleeding, cramping or infection. There also is a small chance of miscarriage.

Does insurance cover it?

In many cases, health insurance plans will cover NIPT and other genetic screening tests, especially when they’re recommended by your doctor. However, insurance providers may have different policies about which tests are covered. To know for sure, contact your insurance company directly to find out your coverage options.

Should I get genetic testing?

There’s a lot to think about when deciding whether to have genetic testing.

These tests can provide important information about your baby, especially if you have risk factors. And some families prefer to have this information, so they can make informed decisions about their baby’s prenatal care and plan ahead for care and support once the baby is born.

However, some families prefer not to know whether their baby is at risk for a birth defect until the baby is born. Getting an abnormal result can be overwhelming. Diagnostic tests are more invasive and can carry some risk to your baby.

Thankfully, genetic counselors are available to walk you and your family through this decision. They can further explain what happens during the testing and any risks involved. They also can help you understand the differences between the genetic tests and which might be best for you. And if you choose to have genetic testing, they can help you better understand the results.

“You can choose to get all genetic screenings done or you can skip them entirely,” said Dr. Krew. “There’s no right or wrong answer. The best decision is the one that’s right for you and your family.”