The objective was to determine the effect of in vitro fertilization (IVF) on nuchal translucency, free beta-human chorionic gonadotropin (Free b-HCG) and pregnancy-associated plasma protein-A (Papp-A) measurements for singleton and twin pregnancies. This was a retrospective population-based register study that included 2921women with 11-13 weeks of gestation singleton and twin pregnancies. All patients were evaluated for the first trimester Down syndrome combined screening. We identify the effect of assisted reproductive technologies (ART) such as in vitro fertilization (IVF) on the nuchal translucency (NT), free beta-human chorionic gonadotropin (b-HCG) and pregnancy-associated plasma protein-A (PAPP-A) values. The study included 2921 patients: 2526 with spontaneous conception (86.5%) and 395 following IVF (13.5%); in our study singleton pregnancies were 2660 (91.1%), dichorionic twin pregnancies 232 (7.9%) and 12 (0.4%) monochorionic twin pregnancies. The mean b-HCG were about 56.67 IU/l (95%CI: 54.98-58.36) in singleton pregnancies and 128.08 IU/l (95%CI: 115.72-140.45) in twin pregnancies. PAPP-A mean values in singleton pregnancies were 3.54 IU/l (95%CI: 3.42-3.66) and 5.25 IU/l (95%CI: 4.46-6.08) in twin pregnancies. The results were statistically significant with p value p�01. There were also significant differences between b-HCG values in spontaneous pregnancies HCG 63.35 IU/l (95%CI: 60.14-64.10) and IVF pregnancies HCG 99.9 IU/l (95%CI: 91.8-107.99) with p value p � 0.01. In our study the IVF had no impact on nuchal translucency values. Free b-HCG levels were higher in twin pregnancies and IVF pregnancies. PAPP-A concentrations were exceeded in twin pregnancies.
Spontaneous and in vitro fertilization pregnancies have comparable first trimester screening profiles for Down syndrome