Even before birth, genetic screening provides insights for family planning

We at Myriad Genetics became champions of genetic testing and screening for a simple reason: to allow providers to empower patients to be proactive about their healthcare.

Whether it’s taking control of their cancer risk or figuring out how a patient may respond to medications used to treat depression, anxiety, ADHD, and other psychiatric conditions, the information gleaned from genetic testing and screening helps patients work with their provider to develop a personalized healthcare management roadmap.

The power of genetic screening is particularly compelling when it comes to helping the next generation. Thanks to enormous scientific advances in what we know about our genome and how we can investigate it, it is now possible to gain insights into our pregnancy health, affording more support options and informed decisions than ever before.

Carrier Screening

For some prospective parents, the first opportunity to use genetic screening comes in the form of carrier screening. Typically performed before pregnancy, carrier screening allows people to find out their risk of passing on serious genetic conditions, such as Cystic Fibrosis or Fragile X syndrome. Some diseases don’t manifest unless both parents pass a non-working genetic variant onto their child; when each parent completes carrier screening, the combined results give us helpful information about inherited health risks a future pregnancy or baby might face.

With the results of carrier screening in hand, prospective parents can consult with their doctors and make educated decisions about the health of their family. For example, a couple found to be at high risk of passing on a certain disease might consider alternatives such as in vitro fertilization or adoption. Or, a couple with a severe disease in their family might find that they do not have the causal genetic change and they can have children without worrying about passing on the disease in their family. In fact, studies show that when patients get carrier screening results, they use it. 77% of patients pursued alternative reproductive options and 37% pursued or planned prenatal diagnosis (Johansen Taber KA et al., Genet Med 2018; https://doi.org/10.1038/s41436-018-0321-0).

Non-Invasive Prenatal Screening (NIPS)

Once a patient is pregnant, NIPS is a useful genetic screening option. NIPS works by finding tiny fragments of DNA from the baby’s placenta that are circulating in the mother’s bloodstream. Because it’s performed with a simple blood draw from the mother, NIPS has rapidly gained traction as an initial screen for chromosome differences. If a pregnancy is found to be at high risk for a chromosomal abnormality, diagnostic tests such as amniocentesis or chorionic villus sampling (CVS) can be used to confirm the results of the genetic screen.

NIPS is used to screen for the health of the developing baby by looking for genetic changes that might indicate an increased risk for a condition such as Down syndrome. Sometimes, NIPS will show an increased risk for a certain condition, but follow-up testing does not find it in the developing baby. While these false positives are rare with NIPS, it is important for patients to understand that they can happen. Therefore, providers need to educate their patients before the screen takes place by informing them about the possibility of both false positives and false negatives (where the screen is negative, but the pregnancy does have the condition). Certified Genetic Counselors can help providers and patients in understanding this information.
If a prenatal screen reports no genetic anomalies, an expectant patient can be more confident that the pregnancy is developing typically — and also avoid higher risks and higher costs associated with amniocentesis and CVS tests conventionally used to evaluate fetal health.

If a health problem is confirmed through diagnostic testing, parents and their physicians can use this important information to make decisions for their family. For example, parents may use the results to plan ahead: some conditions may be lessened or even reversed entirely with interventions during pregnancy or shortly after birth. Having the genetic results from NIPS empowers parents to be prepared and make informed decisions.

Check out the video below to learn more about genetic screening and testing.