Comparison of First Trimester Screening for Down’s Syndrome Using Free Beta-Human Chorionic Gonado-tropin and Pregnancy-Associated Plasma Protein-A Levels between Spontaneous and IVF Pregnancies at 12 Weeks of Gestation

Objective The purpose of this study was to compare Free Beta-HCG and PAPPA levels in single normal and under IVF pregnancies 11-13w + 6d of gestational age. MaterialsAndMethods In this observational study that was performed as a cohort, 300 consecutive single IVF pregnancies and 700 single normal pregnancies were enrolled about 11-13w + 6d of gestational age and Free Beta-HCG and PAPPA was compared across the groups. Results The results in this study demonstrated that PAPPA (P=0.026) was significantly lower and beta-HCG (P=0.030) was significantly higher in IVF pregnancies. The other factors including NT (Nuchal Translucency) and CRL (crown to rump length) and demographic characteristics were not significantly differed across the groups (P > 0.05). Conclusion : This study showed that, PAPPA are lower and Free Beta-HCG is higher in single IVF versus normal pregnancies. It could be related to different placentation in ICSI technique because of alteration in oocyte cytoplasm. Therefore, these markers may be need to adjustment in ART conceptions. Further research should be done to obtain optimal cut-off for these markers in first trimester screening for Down syndrome in ART pregnancies.