Maternal age trends support uptake of non-invasive prenatal testing (NIPT) in the low-risk population.

Purpose: To examine trends in patients submitting samples for cell-free DNA screening to determine whether they reflect a shift towards NIPT use in the low-risk population. Methods: A review of demographic information was performed for all specimens submitted to the Ariosa Diagnostics clinical laboratory for the Harmony (R) prenatal test between January 1, 2014 and December 30, 2017. The proportions of specimens for patients under 35 years and 35 years and older were compared. Results: There was a significant increase in the proportion of specimens submitted by patients under 35, from 47.3% in 2014 to 60.3% in 2017 (Chi-square test, p < .001). Conclusions: The proportion of samples submitted to our laboratory by patients under 35 years has significantly increased in the 4-year subset, which represents the demographics of a diverse group of patients from across the globe. This suggests an increase in uptake of NIPT in the low-risk population.