Comparison of indications and results of prenatal invasive diagnostic tests before and after the implementation of the use of cell-free fetal DNA: a tertiary referral center experience.

PURPOSE: In this study, we aimed to compare the changes in the number, yield, and the percentage of karyotyping indications of the invasive prenatal diagnostic tests between the periods before and after cell-free fetal DNA was introduced to clinical use.
METHOD: The number of invasive prenatal diagnostic procedures such as amniocentesis and chorionic villus sampling, indication percentages and karyotype results in the periods before (January 1, 2009-December 31, 2010), (n = 1412) and after (January 1, 2016-December 31, 2017), and (n = 593) the introduction of cell-free fetal DNA was retrospectively evaluated.
RESULTS: When compared with the period before cell-free fetal DNA came into clinical use, the number of invasive prenatal diagnostic tests decreased by 58% while their yield was found to have increased (4.4% vs. 10.3%) in the period after cell-free DNA began to be used (p < 0.001). While there was a decrease in the indications due to advanced maternal age, an increase was found in ultrasonography indications for structural anomaly and the risk of a single-gene disorder (p < 0.001). Amniocentesis rate was found to have decreased in invasive prenatal diagnostic procedure types, while an increase was reported in CVS rates (p < 0.001).
CONCLUSIONS: Invasive prenatal diagnosis gradually decreases over the years, but the yield of invasive prenatal diagnostic tests increases. In parallel with the rapid development of modern molecular technologies and cheaper and easier access to the tests, we think that the number of invasive prenatal diagnostic tests will experience a more dramatic decrease in the following years.