Sept. 10, 2026—A research study by ARUP Laboratories clarifies the clinical value of atypical findings from prenatal cell-free DNA screening and their impact on pregnancy outcomes. The study, which investigated the connection between atypical prenatal cfDNA screening results and the diagnostic yield of follow-up testing, found that atypical findings frequently indicate clinically relevant diagnoses (Whitham R, et al., Genet Med. Sept. 7, 2026. doi.org/10.1016/j.gim.2026.102713).
“No one has conducted a study as large as this on atypical findings,” Katie Rudd, PhD, ARUP medical director of cytogenetics and genomic microarray and study coauthor, said in an ARUP news release. She and her peers analyzed more than 10 years of data and more than 200 cases with atypical cfDNA findings and follow-up prenatal, postnatal, or maternal testing.
The authors found that 50 percent (102/204) of atypical cfDNA cases had at least one abnormal result identified by follow-up diagnostic testing. Of these cases, 55 abnormal results were determined to be pathogenic, 18 identified variants of uncertain significance, and eight were likely benign. Copy number variations were the most common diagnostic finding, but findings also included aneuploidy, chromosome rearrangement, and others.