Mid-gestation Down syndrome screening test and pregnancy outcome among unstimulated assisted-conception pregnancies

Objectives. Alteration of mid-gestation serum markers in assisted-conception pregnancies is believed to be attributable to ovarian superovulation treatment modalities. We compared alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), and unconjugated estriol (uE₃) in two groups of unstimulated assisted-conception pregnancies, that is, own-oocyte frozen embryos (own-FET) versus oocyte-donated (OD) embryos. Methods. Forty-three OD-conceived and 31 own-FET-conceived singleton parturient women (aged 29 ± 4 years and 31 ± 4 years respectively, P < 0.05) were followed from embryo transfer throughout pregnancy. Results. The daily pattern of first-trimester serum β-hCG was similar in both groups. The OD group had only significantly increased AFP concentrations compared to the own-FET group (1.38 vs 0.99 median MoM respectively, P = 0.002). Although there were no chromosomal abnormalities and no fetal or neonatal deaths in either group, 12% OD women and 6.5% own-FET women were found screen-positive. Eight OD women and 11 FET women had an adverse obstetric outcome (P = NS). Conclusion. OD embryos are a unique clinical model for evaluating the uterine compartment and its contribution to mid-gestation serum marker secretion.