Altered first-trimester screening markers after IVF/ICSI: no relationship with small-for-gestational-age and number of embryos transferred

First-trimester serum markers in 110 in-vitro fertilization (IVF) and 331 intracytoplasmatic sperm injection (ICSI) pregnancies were compared with 1431 pregnancies with spontaneous conception. Alterations of serum markers were evaluated with respect to small-for-gestational-age (SGA) growth and number of embryos transferred. For pregnancy-associated plasma protein A (PAPP-A), significantly lower concentrations were observed in IVF and ICSI pregnancies compared with controls (0.86 and 0.9 versus 1.06; P < 0.001). Free β-human chorionic gonadotrophin (βHCG) values were significantly higher in the IVF/ICSI groups than in controls (1.1 and 1.1 versus 0.94; P < 0.005). IVF and ICSI pregnancies showed higher rates of SGA (10.0% and 8.2%) compared with natural conception (4.6%), but differences in PAPP-A concentrations remained significant (P < 0.005) after the exclusion of SGA pregnancies. No relationship between serum values and the transfer of one, two or three embryos was observed. Centre-specific corrections may be needed to adjust screening parameters for assisted reproductive technology.