Clinical Utility and Incremental Yield of Expanded Prenatal Molecular Genetic Screening for the Detection of Clinically Relevant Fetal/Newborn Disease in the General Population
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Rebecca Hook
Co-PIs: Thomas Westover, Sarah Toledo
College:
College of Health Professions and Human Services
Major:
Genetic Counseling
Faculty Research Advisor(s):
Laura Limone
Abstract:
Non-invasive prenatal testing (NIPT) is the process of sequencing placental DNA from maternal blood to assess the likelihood of a fetus being affected with a chromosomal condition. Per professional guidelines, NIPT is considered standardized care offered to all pregnant patients, regardless of age, to enable early risk assessment for common chromosomal conditions identified in liveborn babies. While previous studies have demonstrated the benefits of expanded NIPT platforms that assess fetal risk for additional chromosomal and genetic conditions, there is limited information on these methodologies within the general-risk population. The purpose of this study was to evaluate the positive predictive value (PPV) and application of two expanded NIPT platforms designed for genome-wide and single-gene use (sgNIPT), within the general obstetric population of a U.S. regional perinatal center. A retrospective chart review was conducted for approximately 12,250 patients who pursued expanded NIPT, with or without reported risk factors, between January 2020 and July 2023. Descriptive statistics were generated via Microsoft Excel 2007. Data analysis was performed with test-positive results and available diagnostic testing results from at-risk pregnancies. Approximately 130 pregnancies screened positive on genome-wide NIPT and 14 pregnanciees screened positive on sgNIPT. PPV was calculated as the total number of true positives divided by the number of true positives combined with the number of false positives. PPV was calculated as 54.08% (genome-wide NIPT) and 61.54% (sgNIPT). While most affected pregnancies were associated with either advanced maternal age, ultrasound findings, and/or family history, several had no high-risk indications and were identified only through routine screening. The findings of this study suggest that implementation of expanded NIPT as part of standardized prenatal screening within the general obstetric population allows for early fetal disease risk assessment of a range of chromosomal and genetic conditions, regardless of identified risk factors.