Diagnostic Testing After Positive Cell-Free DNA Screening for Sex Chromosome Aneuploidies: Clinical and Socioeconomic Determinants.

Objective: To assess socioeconomic and medical factors associated with prenatal confirmatory diagnostic testing after positive prenatal cell-free (cfDNA) screening for sex chromosome aneuploidies (SCA) in a diverse contemporary patient cohort.

Methods: We conducted a retrospective cohort study of patients who had abnormal prenatal cfDNA screening results indicative of SCA and were seen for genetic counseling between 2014 and 2024 at two tertiary academic medical centers. We used logistic regression analysis to evaluate the association of demographic and clinical factors with confirmatory testing.

Results: Of the 692 patients with abnormal cfDNA results, 26% (n = 180) underwent diagnostic testing. These patients were older, resided in more affluent areas, presented earlier for genetic counseling, were more likely to have commercial insurance, and were less likely to prefer Spanish or use an interpreter. Compared to Non-Hispanic (NH) Whites, diagnostic testing rates were higher for NH Asians but were lower for NH Blacks and Hispanics or when results indicated XYY or XXX. In logistic modeling, lower deprivation scores and commercial insurance were independently associated with higher testing rates.

Conclusion: Only 1 in 4 patients pursued prenatal diagnostic testing following positive cfDNA screening for SCAs. Race, ethnicity, socioeconomic status and preferred language were the primary determinants of testing.