For those who want as much information about the health, prospect, and potential for genetic abnormalities in their babies, there are a variety of prenatal screenings we can offer to detect many disorders before birth. Some of these tests, such as amniocentesis and chorionic villus sampling (CVS), are invasive diagnostic procedures that allow us to count the number of chromosomes and even search for deletions of specific segments of DNA that would indicate a genetic disorder.
Noninvasive prenatal screening (NIPS) is a blood test performed on the pregnant patient, designed to screen for chromosome abnormalities.
Currently available tests that can be done with invasive, diagnostic tests, CVS, or amniocentesis detect many of the most common genetic disorders, including chromosome abnormalities such as Down syndrome, and microdeletions or duplication syndromes such as DiGeorge syndrome.
A new addition to noninvasive screening can screen for single gene disorders. A single gene disorder is a disease or condition caused by a change in just one gene (a very small segment of DNA). These disorders would not be picked up on a standard amniocentesis unless the doctors have specifically requested that a gene be examined.
If noninvasive screening shows a high risk for a specific gene disorder, then your doctor can order that test on your CVS or amniocentesis specimen.
What is Vistara?
Vistara is a non-invasive prenatal screening (NIPS) test that detects single-gene mutations, additions, or deletions that cause conditions that might be missed by other available screening tests in the first trimester. At Carnegie Hill Imaging for Women and Maternal Fetal Medicine Associates, we now offer Vistara, a noninvasive prenatal screening for single gene disorders offered by Natera. Vistara screens for over 20 conditions, including Noonan syndrome, achondroplasia, and osteogenesis imperfecta. Combined, these conditions occur in one in 600 births.
The screening takes a small sample of the mother’s blood to isolate cell-free DNA (cfDNA) that originate in the placenta but is now circulating in the mother’s bloodstream. This sample can be taken for several reasons, including:
- Parents who want to know the most information possible
- Anomalies detected during ultrasound
- As a complement to information learned during CVS or amniocentesis
Why Screen for Single-Gene Disorders?
The single-gene disorders that are screened for can affect the pregnancy care path, delivery techniques, after-birth treatment or monitoring, and long-term care of the child. Some of the conditions are detectable by ultrasound, but maybe not until the second or third trimester. This isn’t to say that these conditions are always life-threatening, but it is a direct tool to help our maternal fetal medicine specialists understand the health of a mother, her baby, and how we can support them through our expertise.
Not everyone chooses to screen for genetic disorders, as they’re committed to caring for their child in whatever way necessary after birth. Some patients might not want the added stress that can come with an abnormal test result. This is a personal decision that each parent makes based on their personal beliefs, and there’s no wrong decision when you’re considering undergoing non-invasive prenatal screening.
Many single-gene disorders are not inherited, so a family history won’t help identify families at risk to developing one of these disorders. When these changes do pop up and cause a condition, it’s known as a “de novo” genetic variant.
Non-Invasive Prenatal Screening in New York City
If you want to know the most about your baby’s genetic makeup to help prepare and make decisions about your pregnancy care, your partners in health at Maternal Fetal Medicine Associates are here to help. We offer comprehensive screening services for anyone who wants them, from your first ultrasound to single-gene disorder screenings. To find out if you might benefit from this test, call our office or contact us online today.