Abstract
Early loss of embryos is a major problem after in vitro fertilization (IVF) and embryo transfer (ET). Because implantation of the embryo is a precondition for an increasing serum β-hCG level, the embryonic development cannot be evaluated during the pre- and peri-implantation period. Early pregnancy factor (EPF) is a marker of the development of the embryo before and during implantation. Therefore serum samples of 82 patients were screened for EPF and β-hCG after IVF/ET. 63% (52/82) of all patients were positive for EPF, 21% (17/82) showed elevated serum β-hCG levels. Clinical pregnancies occurred in 12 patients (15%) resulting in nine deliveries. After difficult ET EPF turned negative more frequently in the peri-implantation period compared to transfers without problems. Emphasis should be directed towards optimizing the placement of the embryos and towards minimizing the trauma of the uterus.