First Trimester Risk Assessment Based on Ultrasound and Cell-free DNA vs Combined Screening

There is an ongoing debate regarding how cell-free DNA (cfDNA) screening can best be incorporated into current prenatal screening algorithms for chromosomal abnormalities. Test performance of cfDNA has been shown to be better that first-trimester combined screening (FTCS). However, the cost of the cfDNA testing is considered too high to adopt as first line screening. Moreover, FTCS includes a detailed ultrasound examination of the fetus with nuchal translucency (NT) measurement that allows for early detection of fetal abnormalities. An approach in which every woman are offered an early anatomy scan along with cfDNA may also be a reasonable option. Recently a randomized controlled trial, including 1,518 women with singleton pregnancy undergoing first-trimester screening, compared the screening performance of FTCS with an approach that uses the combination of a detailed ultrasound examination and cfDNA analysis. The trial showed that first-trimester risk assessment for trisomy 21 that includes a detailed ultrasound examination along cfDNA was associated with a significant reduction in the false-positive rate compared with FTCS. This approach obviates the need for maternal serum free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A in screening for fetal aneuploidy. Despite robust evidence on the very high detection rate of cfDNA in detecting trisomy 21, literature is lacking on data regarding women's experience and emotional well-being and satisfaction after test-results of women offered cfDNA compared to those offered FTCS.