Determinant of Prenatal Diagnostic Testing Among Women with Increased Risk of Fetal Aneuploidy and Genetic Disorders.
Objective: This study aimed to assess factors that influence patients’ decisions in accepting prenatal diagnostic testing following genetic counseling for increased risk of fetal aneuploidy. Methods: A retrospective cohort study of women at increased risk of fetal aneuploidy who had genetic counseling from January 2012 to December 2016 at a single academic center. Demographics, indications for genetic counseling and rates of diagnostic testing were collected and compared between those who accepted diagnostic testing and those who chose cell free DNA. The variables were analyzed using chi-square, Fisher exact test, and multiple logistic regression. Result: Of the 2373 pregnant women who underwent genetic counseling for increased risk of fetal aneuploidy during the study period, 321 women had diagnostic testing (13.5%). Women at 35 years and older accepted diagnostic testing more than women younger than 35 years (20.7% versus 11.5%, p < 0.001). Asian women accepted diagnostic testing at 27.7% more than white, non-Hispanic Black and Hispanic women at 18.0%, 12.1% and 11.7% respectively, p = 0.002. Number of indications for genetic counseling influenced the likelihood of accepting diagnostic testing. Women with one indication had 11.5% acceptance of diagnostic testing; and with two and three indications, it was 17.0% and 29.2% respectively. The commonest indication for diagnostic testing was cystic hygroma (RR 7.5, 95% CI 3.12-8.76 p < 0.001). The relative risk of diagnostic testing for fetuses with shortened long bones; femur and humerus, thickened nuchal fold, echogenic bowel, single umbilical artery, increased nuchal translucency were 4.0, 3.3, 3.1, 2.7, and 2.7 respectively. Abnormal serum analyte alone was associated with less acceptance of diagnostic testing (RR 0.8, 95% CI 0.7 – 0.96, p = 0.017). Conclusion: Age, race, ethnicity and cumulative number of indications for genetic counseling influenced acceptance of diagnostic testing in at-risk women of fetal aneuploidy and genetic disorders