Population-based trends in the prenatal diagnosis of sex chromosome aneuploidy before and after non-invasive prenatal testing

Abstract

Objective: To assess the impact of non-invasive prenatal testing (NIPT) on trends in the prenatal diagnosis of sex chromosome aneuploidy (SCA) in a population with >73,000 annual births. Method: Retrospective population-based cohort study from 1986–2016 of all women undergoing prenatal diagnosis before 25 weeks gestation in the Australian state of Victoria. Statistical significance was tested using the chi-square test for trend or proportions. Results: There were 2,043,345 births and 842 SCA diagnoses from 1986–2016. The percentage of prenatal diagnostic tests leading to a SCA diagnosis increased significantly from 0.95% in 2010 to 2.93% in 2016 (p < 0.001) but due to a concurrent decline in..