by Libby Valenti, MS, CGC, Director, Women’s Health MSL, Natera™
Although prenatal genetics is not a new concept, it is important to consider how innovations in the field impact discussions with your patients. Evolving American College of Obstetrics and Gynecology (ACOG) guidance and changing insurance coverage for relevant tests have critical implications for patients’ prenatal choices. Below are 3 things to consider when talking with your patient about prenatal genetic screening:
Does your patient want to know their risk of having a baby with a chromosomal condition?
Patients who have known someone with a chromosome condition can have an inflated idea of how common these conditions are, whereas others could believe their child is immune from these conditions. Confirming that patients recognize that 3% of babies are born with defects, and that the most common chromosome conditions are not hereditary can be a beneficial way to begin the conversation around prenatal genetic screening.1
Regardless of how your patient could feel about their risk, they should know that tools exist that can help them make well-informed decisions for themselves and their families. Through your discussions with them, your patients should gain an understanding of the 3 general options for gaining insight into whether their baby could have a chromosomal condition.
You can explain that while diagnostic testing is the only way to get definitive information, screening can provide information on the likelihood that a chromosomal condition is present.2 Critically, patients should also understand that if they opt to forego all testing, they could be missing an opportunity to prepare emotionally and practically for the future.
Does your patient understand their options?
If your patient is interested in more information on their risk for a chromosomal condition, the next matter to discuss is their specific testing options, and the relevant pros and cons of each. Specifically, you should communicate that the benefit of non-invasive screens is that they pose no risk to the baby, whereas the benefit of diagnostic tests is that they provide a more definitive answer on whether a chromosomal condition is present.
If the patient prefers a non-invasive screen, they should be told that ACOG, the organization that provides clinical guidance to OBGYNs, recently changed its prenatal care guidelines to emphasize the importance of allowing all women access to one type of screen – non-invasive prenatal testing (NIPT) – because of its high degree of accuracy. Patients should also be educated about multiple marker screening (MMS). They should be informed that this approach has been used longer than NIPT, but that it is more likely to produce false results, and it cannot be conducted until later in pregnancy.3
On the other hand, if diagnostic testing is the choice for the patient, then options like CVS and amniocentesis should be discussed. The patient should know that chorionic villus sampling (CVS) can be done earlier in pregnancy and furthermore, whether these tests are available locally or not.4
Is your patient prepared for the results?
As soon as a patient decides to pursue prenatal genetic screening or diagnosis, she should be made aware of what she can expect from the results and how those results could influence her decision making. With diagnostic testing, should they receive a positive result, patients should understand that they will be given resources to provide accurate information and to help them choose their next steps.
With non-invasive screens, the conditions that are included on the screening test and the lack of definitive answers should be reiterated, and patients should be made aware that if their results suggest that they are at high risk for having a baby with a chromosomal condition, they will be advised to receive genetic counseling to review the option of invasive testing for confirmation. It is also important for patients to be aware that they could have to provide a second sample if the first sample does not contain enough fetal DNA to produce a result.
As prenatal genetics options expand and the evidence about these options accumulates, we need to consider how we can best equip our patients with the information they need to make the best decisions for themselves and their families. Given the recent update to the ACOG guidelines that recommends that NIPTs be made available to all pregnant women, clear communication on this option is imperative for OBGYNs. While NIPTs are not right for all women, the important information that they can provide, without significant safety risks or concerns over false results, should be conveyed. The implications of older screening options or more invasive tests, including diagnostic testing, should continue to be covered.
For more information on discussing prenatal genetics with your patients, view this video.
- Data & Statistics on Birth Defects | CDC. Accessed March 3, 2021. https://www.cdc.gov/ncbddd/birthdefects/data.html
- Hardisty EE, Vora NL. Advances in genetic prenatal diagnosis and screening. Current Opinion in Pediatrics. 2014;26(6):634-638. doi:10.1097/MOP.0000000000000145
- Screening for fetal chromosomal abnormalities. Obstetrics & Gynecology. 2020;136(4):859-867. doi:10.1097/AOG.0000000000004107
- Alfirevic Z, Navaratnam K, Mujezinovic F. Amniocentesis and chorionic villus sampling for prenatal diagnosis. Cochrane Database of Systematic Reviews. 2017;2017(9). doi:10.1002/14651858.CD003252.pub2