Prenatal Genetic Diagnostic Testing in the Era of Cell Free Fetal DNA For Aneuploidy Screening [10D

Abstract

INTRODUCTION: Prenatal screening for fetal aneuploidy has improved tremendously since the incorporation of cell-free DNA (cfDNA) in to the genetic screening armamentarium. Despite its improved detection rate of aneuploidy, this remains a screening tool and not designed to provide diagnostic information. This study aimed to assess whether initiation of cfDNA screening at the University of Illinois at Chicago (UIC) in January 2012 influenced the acceptance of prenatal diagnostic testing in at-risk women. METHODS: Retrospective study of two cohorts of women who received prenatal genetic counseling at UIC: pre-cfDNA era from January 2010 to December 2011 and cfDNA era from January 2012 to December 2016. Charts of eligible patients were reviewed; demographics, indications for genetic counseling and acceptance of diagnostic testing were analyzed. Statistical tests: Chi-square, Fisher exact test, Student t-test, bivariate and multivariate analysis were utilized. RESULTS: A total of 2371 women had genetic counseling at UIC from 2010 to 2016; 629 prior to cfDNA and 1741 after. There were 319 women who had diagnostic testing, 168 (26.7%) during pre-cfDNA era vs. 151 (8.7%) in the cfDNA era, RR 4.0 (95% CI 3.1-5.0), p<0.001. Multivariate analysis using Mantel-Haenszel test revealed that pregnant women prior to availability of cfDNA were more likely to pursue prenatal genetic diagnostic testing, and it remained statistically significant even after controlling for confounders, RR 1.20 (1.18-1.23), p<0.001. CONCLUSION: Advent of cfDNA as prenatal screening was associated with decreased utilization of diagnostic prenatal testing in women whose offspring were at risk of chromosomal abnormalities.