How genetic testing can help moms-to-be

It’s been 15 years since scientists announced they had identified and mapped all the genes of the human genome. That groundbreaking work has made an incredible impact on prenatal care and pregnancy planning, as moms-to-be can now get more information than ever before about their babies before they are born — and even before they become pregnant.

Genetic testing today

It used to be that testing for genetic abnormalities meant having an invasive procedure like amniocentesis or chorionic villus sampling (CVS) — both of which carry a small risk of losing the pregnancy. Because of this potential danger, they were only offered to moms with a clear risk of a genetic disorder.

Now, expectant moms are routinely screened through non-invasive prenatal testing (NIPT), a simple blood test that can be performed as early as nine weeks gestation. This test screens for common fetal aneuploidy — an abnormal number of chromosomes in cells — which can cause conditions such as trisomy 18, 13 and Down syndrome.

The NIPT itself does not confirm or exclude a diagnosis, however. There can be false positives or false negatives, but in general the test has a high enough sensitivity to make it a good screening tool. Moms who screen positive for fetal aneuploidy are often referred to a specialist to confirm diagnosis and receive appropriate counseling.

Diagnostic testing

The Fetal Concerns Center at Children’s Wisconsin is a multidisciplinary center, with various specialists skilled in caring for pregnant mothers who are facing a potential fetal diagnosis or concern.

Women are usually referred to the Fetal Concerns Center based on either an abnormal NIPT screening or an abnormal ultrasound. The Fetal Concerns Center manages all aspects of a mom’s prenatal care, including coordinating diagnostic testing and genetic counseling through the Genetics Program at Children’s Wisconsin.

Diagnostic testing is used to identify specific genetic conditions. It can identify potentially treatable diseases prenatally and confirm a suspected diagnosis. Knowing about fetal conditions before birth allows for immediate treatment after birth, and sometimes even in utero.

Another kind of non-invasive testing is called carrier testing, which tells parents whether they carry a gene for certain genetic disorders. Parents may have carrier testing for a variety of reasons:

• Family history of a specific disorder
• Screening for disease that is more common in certain ethnic groups or races
• Parents want to screen for a variety of genetic disorders, regardless of family history, race or ethnicity

Genetic counseling

In addition to state-of-the-art testing and research, The Fetal Concerns Center has genetic counselors who are experts in helping families understand their diagnosis, as well as possible outcomes and choices.

We know every family is different, and we work with parents to help them understand potential outcomes and how different courses of treatment may affect those outcomes.

All prenatal genetic testing is designed to help parents — and their doctors — make informed decisions about a pregnancy. It also helps the team know how to plan for a birth and what to expect.

If you have questions about genetic testing, talk with your OB/GYN or contact the Fetal Concerns Center at Children’s Wisconsin at (414) 337-4776.

Donald Basel, MD Medical Director Genetics and Genomics Program

The Children's Wisconsin Genetics and Genomics Program is a leader in genetic treatment and research for children and adults with concerns about genetic conditions and related issues. Our team can diagnose, educate, counsel and treat patients with a variety of genetic conditions. We work with our patients and their families to develop care plans including genetic counseling, medical care and referrals to other specialists.