First trimester screening for Down's syndrome after assisted reproductive technology: non-male factor infertility is associated with elevated free beta-human chorionic gonadotropin levels at 10-14 weeks of gestation.

We retrospectively compared the first trimester Down's syndrome serum screening markers free beta-hCG (fbetahCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11-14 weeks of gestation in 4,088 women with naturally conceived pregnancies and in women pregnant after ICSI (n = 163), IVF (n = 59) and frozen-thawed embryo transfer (n = 31), and we searched for a potential relationship between infertility cause and marker levels. We found lower serum PAPP-A levels in pregnancies after IVF and ICSI compared with spontaneously conceived pregnancies and non-male factor infertility was associated with elevated serum fbetahCG levels at 11-14 weeks of gestation.