Indications for Invasive Prenatal Testing before and after Noninvasive Prenatal Screening

Objective To evaluate changes in indications for genetic testing after introduction of noninvasive prenatal screening (NIPS) into a single center. Pregnancy outcomes and results of testing were evaluated. Study Design It was a retrospective cohort study. Medical records were reviewed for all invasive testing procedures from January 1, 2007, to December 31, 2015. NIPS was introduced in February 1, 2012. Indications were compared before and after that date. Results of genetic testing and pregnancy outcome were also obtained from the medical records where available. Results A total of 2,066 invasive diagnostic procedures were performed. Significantly fewer invasive procedures were performed per month following introduction of NIPS (23 vs. 13). Indications were less likely to be reported as advanced maternal age (AMA), abnormal genetic screening, and abnormal ultrasound findings following introduction of NIPS (p < 0.0001). No difference was noted for parental chromosome abnormality, risk of single-gene disorder, or prior child with aneuploidy. Tests performed after introduction of NIPS were more likely abnormal (16.3 vs. 27.6%; p < 0.0001).Total number of pregnancy terminations decreased (130 vs. 123); more were terminated after prenatal diagnosis following NIPS introduction (12.9 vs. 30.1%). Conclusion Since the introduction of NIPS, fewer invasive tests are performed. Indications have changed since NIPS was introduced, becoming less common for AMA, abnormal genetic screening, and abnormal ultrasounds.