A trip to the OB/GYN consists of many emotions, ranging from the joy and anticipation of hearing about and viewing your new baby to the anxiety and fear caused by questions such as “what if…” and “is everything how it should be?” Moreover, in the case of prenatal testing, anxiety can increase ten-fold when thinking of blood samples and needles in the wrong places. While not much can be done to soothe the general anxiety surrounding the baby’s birth, new technology in the form of noninvasive prenatal screening has been designed to test for inherited disease variants. This acts as a step up from previously invasive procedures such as amniocentesis and chorionic villus sampling (CVS), which similarly screens for genetic health conditions passed on to the fetus, albeit via differing mechanisms. Amniocentesis involves using a needle to collect amniotic fluid in the uterus, while CVS utilizes a needle to remove a placental sample for subsequent genetic analysis.³

This innovative development by researchers from hospitals in the greater Boston area such as Massachusetts General and Boston Children’s in collaboration with the Broad Institute of MIT and Harvard, is known as non-invasive prenatal testing (NIPT). After administering a blood test on a patient, NIPT technology is able to screen the blood sample for changes in fetal chromosomes, and can detect mutations such as trisomy 21 (an extra copy of Chromosome 21 which causes Down Syndrome), loss and gain of chromosomes, and other chromosomal variants which may affect fetal development and DNA.²

Behind the scenes, a research study collected data from 51 pregnancies across all trimesters. Sequencing almost 23,000 genes, NIPT technology pinpointed relevant single-nucleotide variants (SNV), which refers to a substitution of one nucleotide for another, and base insertions and deletions through machine learning software to detect aneuploidy, or an abnormal number of chromosomes.¹ Additionally, this test has proven to be highly sensitive in distinguishing between fetal and maternal SNV, allowing for isolated analysis of the fetal DNA. The study has already found that the sex of the baby and 100% of the variants found from invasive testing was also detected by noninvasive testing.¹ However, the testing for insertion and deletion has greater false positive results in both NIPT and invasive testing, meaning that these tests may identify a difference when there is none.¹ Further testing and development will likely allow for greater accuracy in this area for NIPT.

These results indicate that NIPT is a suitable alternative to current invasive prenatal testing methods. With decreased reliance on amniocentesis and CVS, noninvasive prenatal testing techniques may significantly help in reducing anxiety around these types of procedures. Also being able to conduct this test in the first trimester will allow expectant parents to make more informed decisions about pregnancy at an earlier stage. Furthermore, this development offers hope for more research and clinical advances in precision medicine and genetic testing for other medical fields. However, if not covered by insurance, NIPT out-of-pocket costs may not reduce healthcare disparities, but rather present the same financial burden as other prenatal testing options.⁴ Therefore, the next steps in implementing this novel technology could lean towards improving costs and methods of payment for this technique to financially differentiate it from available invasive prenatal testing procedures. Ultimately, the development of NIPT technology is a big step in the right direction towards a more inclusive and accessible healthcare experience, especially for the youngest members of our society and the ones bringing them into the world.

References

1. Brand, H., Whelan, C. W., Duyzend, M., Lemanski, J., Salani, M., Hao, S. P., Wong, I., Valkanas, E., Cusick, C., Genetti, C., Dobson, L., Studwell, C., Gianforcaro, K., Wilkins-Haug, L., Guseh, S., Currall, B., Gray, K., & Talkowski, M. E. (2023). High-Resolution and Noninvasive Fetal Exome Screening. The New England Journal of Medicine, 389(21), 2014–2016. https://doi.org/10.1056/nejmc2216144
2. Massachusetts General Hospital. (2023, November 22). Researchers develop new method for prenatal genetic testing. Medicalxpress.com; Medical Xpress. https://medicalxpress.com/news/2023-11-method-prenatal-genetic.html#google_vignette
3. Mayo Clinic Staff. (2020). Genetic testing – Mayo Clinic. Mayoclinic.org; https://www.mayoclinic.org/tests-procedures/genetic-testing/about/pac-20384827
4. van, Kooij, C., Bekker, M. N., Galjaard, R.-J. H., & Henneman, L. (2021). Non‐invasive prenatal test uptake in socioeconomically disadvantaged neighborhoods. Prenatal Diagnosis, 41(11), 1395–1400. https://doi.org/10.1002/pd.6043

Image References

Cover Image: tasty_cat. (2024). Noninvasive prenatal testing NIPT concept. Adobe Stock. https://stock.adobe.com/images/noninvasive-parental-testing-nipt-concept-vector-flat-healthcare-illustration-genetic-test-baby-in-womb-blood-vessel-dna-spiral-symbol-design-for-healthcare-pharmacy-family-planning/446627818?prev_url=detail