No abstract

ADAM12-s and PAPP-A levels are altered in several subgroups of ART pregnancies. Larger studies are required to confirm these findings.

Over the last three decades, prenatal screening for Down syndrome and other chromosomal abnormalities has become routine during antenatal care. Down syndrome screening has changed from the second to the first trimester of pregnancy because of the higher detection rate and earlier diagnosis. Second-trimester screening, based on the combination of maternal serum human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), and unconjugated estradiol (uE3) as a function of maternal age, yields a detection rate of 60% with a falsepositive rate (FPR) of 5% (Wald et al., 1988). In standard practice, first-trimester screening, which combines maternal age, nuchal translucency thickness (NT), and maternal serum free beta-human chorionic gonadotropin (fβ-hCG), and pregnancy-associated plasma-protein-A (PAPP-A), can achieve a detection rate 90% with a FPR of 5% (