RESUMO
OBJECTIVES: To assess the determinants associated with the use of analysis of cell-free DNA in maternal blood for detection of trisomy 21 in high-risk women. MATERIALS AND METHODS: Prospective study conducted in a single center between July 15, 2014 and December 15, 2014 on 99 consecutive women with increased risk of trisomy 21 above 1/250. RESULTS: Analysis of cell-free DNA in maternal blood for detection of fetal trisomy 21 was proposed to 95 women out of 99, among them, 43 women (45.3%) required the test. Among these 43 women, 17 (38.6%) had a higher socio-economic status versus 10 (19.2%) among the women who did not request the test (P=0.03). The most common reason given by the 52 women who did not request the analysis of cell-free DNA was the cost, for 30 of them (57.7%), then because the test was not providing certainty for the diagnostic of trisomy 21 for 23 women (44.2%). CONCLUSION: Analysis of cell-free DNA on maternal blood for detection of trisomy 21 does not seem accepted by the majority of women. The cost is probably the main reason for not using this test, but it seems that the lack of diagnostic certainty is also an obstacle for some women.