Cell-Free DNA Prenatal Screen: Q&A

The Mayo Clinic Cytogenetics Laboratory recently released an updated version of the Cell-Free DNA Prenatal Screen (ID: NIPS). This test detects common chromosome abnormalities without the risk of pregnancy loss associated with invasive prenatal procedures. Q: What is cell-free DNA prenatal screening?  A: Cell-free DNA prenatal screening is a type of noninvasive prenatal screening that detects certain chromosome abnormalities in the fetus. The test (ID: NIPS) examines small pieces of placental DNA circulating in maternal blood. The results of this screen provide patients with information regarding the chance that their fetus may have a chromosome abnormality but does not provide a definitive diagnosis. The Mayo Medical Laboratories Cell-Free DNA Prenatal Screen is available to women after 10 weeks of pregnancy and used to detect trisomies 21 (Down syndrome), 18 (Edwards syndrome), and 13 (Patau syndrome) and aneuploidies of the X and Y chromosomes such as monosomy X (Turner syndrome) and XXY (Klinefelter syndrome). Q: What are the current guidelines/recommendations for cell-free DNA prenatal screening?  A: The American Congress of Obstetricians and Gynecologists (ACOG) recommends that all patients receive detailed counseling regarding the benefits and limitations of current prenatal screening options, including cell-free DNA screening. Patients should evaluate with their health care provider the most appropriate screening or diagnostic testing option based on their age, family history, presence of ultrasound abnormalities, and results of other screening methods. Mayo Medical Laboratories will accept samples for cell-free DNA screening from all pregnancies, regardless of risk factors starting at 10 weeks gestation. Specimens are also accepted from multiple gestations, though the predictive value may be lower than that of a singleton pregnancy. Q: What type of support is available for physicians and care providers ordering NIPS? A: The Cytogenetics Laboratory has several dedicated genetic counselors available Monday through Friday, 8 a.m. to 5 p.m. CT, to assist clients with understanding the results of the NIPS assay. Clients can call Mayo Medical Laboratories at (800) 533-1710 and request to be transferred to a genetic counselor for NIPS testing. During off-hours, clients can leave contact information with the customer service representative, and the genetic counselors will return the call the next business day. Q: What billing services are available for NIPS testing?  A: Mayo Medical Laboratories offers third-party billing, insurance prior authorization, and patient financial assistance to our clients and their patients. Prior authorization forms will be included in the supply kit. Receipt of the prior authorization form will trigger the extractand-hold process where the laboratory stabilizes the DNA while the billing office determines insurance coverage. If the patient outof-pocket cost will be greater than $200, Mayo Medical Laboratories will contact the patient to determine if testing should continue. Third-party billing without insurance pre-authorization is available by requesting this service through the billing office. Patient financial assistance may be available to those who qualify. Patients who receive a bill from Mayo Medical Laboratories will receive information on eligibility and how to apply. Q: What patient populations can use the Mayo Medical Laboratories Cell-Free DNA Prenatal Screen? A: Although current guidelines recommend cell-free DNA prenatal screening for high-risk pregnancies, any patient may choose this screening method. Mayo Medical Laboratories will accept samples from patients regardless of their risk of aneuploidy. Specimens from twin gestations and pregnancies utilizing egg donors or gestational carriers will also be accepted. It should be noted that results for these types of gestations may not be as accurate. Q: Why doesn't the Mayo Medical Laboratories NIPS test include screening for microdeletions?  A: ACOG does not recommend routine screening for microdeletion syndromes (e.g., DiGeorge syndrome, Cri-du-chat syndrome). Microdeletion syndromes are rare and, unlike the autosomal trisomies, their incidence rate is not related to maternal risk factors such as advanced age. There is currently very little published data on the clinical test performance of screening for microdeletion syndromes, so the actual positive predictive value in a clinical setting remains unknown. However, given the rarity of these disorders, the positive predictive value is expected to be low. Q: What diagnostic tests for fetal aneuploidy are available as an alternative or follow-up to screening? A: Noninvasive prenatal screening is not diagnostic, and patients with positive/abnormal results should be offered diagnostic testing to confirm the results. Invasive prenatal tests (i.e., those performed on amniotic fluid or chorionic villus) are considered diagnostic and are available through Mayo Medical Laboratories. For additional information on noninvasive prenatal screening, please call 800-533-1710.
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This post was authored by the Marketing Team at Mayo Clinic Laboratories.