Background: There are few studies on the uptake of non-invasive prenatal screening, but those available suggest substantial variation in uptake in the initial years in which it was offered. There is a need to update the earlier evidence and determine whether there has been any change in usage trends as the number of users have increased. This will help inform policy makers about NIPT uptake under currently existing policies and guidelines which can help inform whether to maintain or refine policies on NIPT. Objectives: The primary objective of this thesis was to investigate recent trends in NIPT utilization, and the secondary objective was to identify differences between pregnant individuals aged 40 years and above and/or with a history of previous aneuploidy who opted for first-tier (first-line screening) or second-tier (contingent screening) NIPT and pregnant individuals aged less than 40 years with no history of previous aneuploidy. Methods: This retrospective cohort study used a province wide birth registry from Ontario and the population studied comprised pregnant individuals with an expected date of delivery from August 1st, 2016 to March 31st, 2020. Results: Of 536,748 pregnant individuals resident in Ontario during the study period, 27,733 were classified as high-risk of giving birth to a baby with a chromosomal aneuploidy and 509,015 were classified as low-risk of giving birth to a baby with a chromosomal aneuploidy. Uptake of NIPT has increased every year since 2016. We found substantial variation in NIPT between regions within the province. Highest uptake was found in urban areas, highest neighbourhood of income and education quintiles, high-risk population, among those with a prenatal care visit in the first trimester, multiple pregnancy, multigravidity, body mass index within the normal range (18.5-24.9 kg/m2), and OHIP funding. Conclusion: Our results suggest a need to provide more education/training about NIPT and funding eligibility to health professionals and pregnant individuals, including low-risk pregnant individuals in the first-tier (first-line screening) NIPT funding policy, to ensure equitable assess.