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® 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.