Second-tier non-invasive prenatal screening for Down syndrome in a public obstetric unit: the first 12 months

Objective: To review the uptake rate of non-invasive prenatal testing (NIPT) in the first 12 months of implementation in the obstetric unit of United Christian Hospital. Methods: Between December 2019 and November 2020, women with a fetal Down syndrome (DS) risk ratio of ≥1:250 after first-trimester DS screening (using maternal serum markers and nuchal translucency thickness on ultrasonography) or second-trimester DS screening (using maternal serum markers) were offered free-of-charge second-tier NIPT or invasive testing. Results of NIPT and invasive testing and pregnancy outcome of these women were reviewed. Characteristics of those opting for NIPT versus invasive testing were compared. Univariate and logistic regression analyses were used to determine significant factors associated with opting for NIPT. Results: During the study period, 2182 women underwent first-trimester DS screening (n=2086) or second-trimester DS screening (n=96). 117 women were screen positive, with a DS risk ratio of