By Chelsea Wagner, Lead Genetic Counselor at BillionToOne
How parents and doctors navigate pregnancy has evolved quickly in recent years. Innovative prenatal screening now makes it possible to learn about a baby’s risk for certain genetic conditions using only a simple maternal blood draw. Having this information early gives families more time to plan, connect with specialists, and consider new treatment options that may improve outcomes, even before birth. This type of screening is reshaping how parents and providers approach pregnancy care.
Understanding Prenatal Genetic Testing
There are two main types of genetic conditions all pregnant people are usually offered screening for—regardless of personal or family history:
- Chromosomal conditions, like Down syndrome, usually occur randomly due to extra or missing chromosomes. Every pregnancy carries a small risk for these conditions, regardless of family history.
- Other conditions, like cystic fibrosis, are inherited, or passed down through families. Parents who carry a gene change related to these conditions are healthy themselves and usually have no symptoms, so most people never know they are carriers. These are called recessive conditions, and a baby can only be affected when both parents are carriers of the same conditions.
Why Test for Genetic Conditions?
While the chance of having a baby with one of these conditions is generally low, learning about risk early in pregnancy gives families time, options, and reassurance. Early screening can help parents:
- Decide whether diagnostic testing is right for them
- Choose a birth plan that’s right for you and your baby, like a hospital with specialized care
- Connect with specialists, like pediatric experts, sooner
- Feel more informed and empowered throughout their pregnancy
Why Screening for Inherited Conditions Matters
The American College of Obstetricians and Gynecologists (ACOG) recommends that all pregnant patients be screened for certain inherited conditions, including cystic fibrosis and SMA. These conditions are more common than most people realize, and carriers typically have no symptoms.
Traditional screening identifies parental carrier status only (whether parents are carriers). New prenatal screening technology goes further and identifies a baby’s risk for certain chromosomal and inherited conditions directly from maternal blood. This innovative approach gives families clearer information sooner – when it can make the biggest difference.
In utero Innovation
One of the most exciting developments in prenatal care is the potential to treat certain genetic conditions before birth. For some conditions, treatments started shortly after birth already lead to life-changing improvement—but emerging research suggests that beginning treatment during pregnancy may offer even greater benefits.
Early fetal-risk assessment can help parents and providers identify which pregnancies may be candidates for today’s treatments as well as future in-utero therapies.
- Spinal muscular atrophy: SMA affects the muscles used for breathing and movement. FDA-approved treatments have been shown to be effective when started as early as possible. Researchers are exploring whether treatment during pregnancy could preserve motor neuron function in the muscles prenatally.
- Cystic fibrosis: CF affects the lungs and digestive system. New medications called CFTR modulators have transformed outcomes for those who start treatment early. Studies are now evaluating whether beginning therapy before birth might resolve certain ultrasound findings and promote pancreatic function.
- Beta-thalassemia & Sickle Cell Disease: These red blood cell conditions cause anemia, organ damage, and other complications. Recently approved gene therapies are creating new possibilities for long-term improvement. Future approaches may allow certain babies to receive treatment before they’re born.
- Alpha thalassemia: A condition that ranges widely in severity. Severe forms can cause complications during pregnancy, sometimes requiring in-utero interventions. Early identification can help ensure that these pregnancies receive specialized care.
A New Direction for Prenatal Testing
Prenatal testing today looks different because medicine is entering a new era—one where early, meaningful information can open the door to life-changing treatment options. Instead of the older, step-by-step approach that requires testing both parents, UNITY is a first-of-its-kind test that uses just one simple blood draw from the pregnant parent to estimate the baby’s risk for both chromosomal and inherited conditions.
This is possible thanks to UNITY’s unique molecular counting technology (QCTs), which can measure tiny fragments of fetal DNA with extraordinary precision. While the science behind it is complex, the promise is simple: clearer answers, earlier in pregnancy, for more families.
By giving clinicians and parents a clear, comprehensive view of fetal risk, they are empowered to take advantage of other advances in prenatal care at the time when early action matters most.
About the Author:
Chelsea Wagner is Lead Genetic Counselor at BillionToOne, a molecular diagnostics company with a mission to create powerful and accurate tests that are accessible to all. The company’s patented Quantitative Counting Templates™ (QCT™) molecular counting platform is the only multiplex technology that can accurately count DNA molecules at the single-molecule level.
