Embryo-derived platelet activating factor, a marker of embryo quality and viability following ovarian stimulation for in vitro fertilization.

Embryo-derived platelet-activating factor (PAF) may be an important mediator of early maternal recognition of pregnancy. PAF was higher in media associated with clinical pregnancies when compared to preclinical pregnancies but not higher in pregnant vs nonpregnant groups. The production of PAF by the preimplantation embryo was not related to follicle size or embryo morphology. However, differences in PAF concentrations in the culture media were related to the age of the embryo culture medium and the developmental stage of the embryo.