Monitoring Embryos after in Vitro Fertilization Using Early Pregnancy Factor

The success of in vitro fertilization (I VF) and embryo transfer (ET) is dependent upon optimizing the efficiency of each step of the procedures that finally lead to embryo replacement. Much effort has been directed at improving oocyte recovery and fertilization through various regimes of ovarian stimulation, oocyte aspiration techniques, and cell culture technology. This has led to rates of oocyte recovery in the region of 80–90% and embryo transfer rates of 60–70%.1–4 By contrast, the pregnancy rate following ET is disappointingly low, being of the order of 15 to 20%.1,2,5,6 This seems to be the step at which most failures of IVF occur.