4 Optional Prenatal Screening Tests Available To You, Explained By Doctors
If you're pregnant, you've probably seen the pamphlets in your doctor's office advertising the various prenatal and genetic tests available to you, but what do they all mean? While your doctor will likely advise you on what tests are recommended for your specific case, there are several prenatal tests you have the option to take, whether your doctor mentions them or not.
Dr. James Grifo, M.D., a reproductive endocrinologist from the obstetrics and gynecology department at New York University's Langone Medical Center, tells Romper that actually, "all tests are optional." Even prenatal tests that have become standard — such as anatomy scans, blood tests that look for blood disorders, and various types of urinalysis — aren't mandatory. They are encouraged, though, so that the your doctor can track you and your baby's health and progress.
Whether or not you choose to take optional prenatal tests to determine your baby's risk of certain health conditions will depend on your individual history and personal choice. For example, if your family history includes genetic or blood disorders, you might opt to take carrier screening tests to determine your baby's risk of inheriting a certain disease. Many of the tests pose no risk to the fetus (in fact, many can be done before you're even pregnant), Dr. Grifo notes. It is also important to consider the costs of these prenatal tests and to have a conversation with your insurance carrier to see if they are covered.
Here are the four most-common categories of optional prenatal tests available right now.
1. Carrier Screenings Before Pregnancy
Some pregnancies are a surprise, and some are very planned. "There are a bunch of things we can screen for before you even get pregnant," Dr. Grifo says, noting that many insurance companies even pay for these pre-pregnancy screenings. He says that there are carrier screening tests that test for 281 recessive genes, which can test for things like cystic fibrosis or Fragile X syndrome.
2. Paternal Genetic Screening
Recessive disorders, such as cystic fibrosis, sickle cell anemia, and Tay Sachs disease, require both parents to carry the gene. If screening tests on the mother reveal a genetic component for a recessive disorder, carrier screening should also be performed on the father, Dr. Grifo explains.
3. Chromosome Abnormality Screenings
Chromosome abnormality screenings are a prenatal testing option in the first trimester that are commonly performed by non-invasive prenatal testing (NIPT) or non-invasive prenatal screening (NIPS), Blair Stevens, M.S., prenatal genetics expert and certified genetic counselor, tells Romper. Because the placenta sheds some of its cells into mom's bloodstream, this test uses the mother's blood to assess baby's risk for Down syndrome and other chromosomal conditions, she explains.
Dr. Shweta Patel, M.D., obstetrician and gynecologist for Orlando Health, says that non-invasive chromosome abnormality screenings can help patients determine if more testing is needed. "If their NIPT is negative, they have saved themselves an otherwise invasive procedure with some risk to the fetus," she says.
4. Fetal Tissue Sampling Tests
The more invasive tests, such as chorionic villus sampling and amniocentesis, are taken by inserting a fine needle into the abdomen or the cervix to draw a sample of the placenta or amniotic fluid, which is then tested. Dr. Grifo notes that these tests carry a minor risk of miscarriage and are something doctors would discuss with patients over the age of 35 or who have previously had a child born with Down syndrome or a neural tube defect like spina bifida.
The major difference is that NIPT screenings only assess the baby's risk of disorders, and amniocentesis and chorionic villus sampling diagnose chromosome disorders and birth defects. "There is the element of having false positives and negatives with the NIPT that is not as prevalent with the invasive test options," Dr. Patel says.
If you're curious about any of the tests mentioned above, have a conversation with your OB-GYN to assess your specific case and medical history.
Dr. James Grifo, M.D., Ph.D, reproductive endocrinologist and program director NYU Langone Prelude Fertility Center
Blair Stevens, prenatal genetics expert with the National Society of Genetic Counselors and certified genetic counselor with McGovern Medical School at UTHealth in Houston
Dr. Shweta Patel, M.D., obstetrician and gynecologist for Orlando Health