OVIDUCTAL FUNCTION IS CRITICAL FOR VERY EARLY HUMAN LIFE

For normal fertilization, the ovum must be picked up from the ovarian surface or from the abdominal cavity into the ampulla. The rapid trans port of gametes includes a complex reorganization of the oviductal smo oth muscle electrical activity that precedes the mechanical activity. The 3-day stay at the ampulla-isthmic junction requires both signals f rom the ovum to the oviduct and vice versa, supporting the ovum and re gulating its to-and-fro movements. Oviductal fluid, a principal factor in tubal function, coats the newly fertilized egg, activates transcri ption and gives a signal for sperm fertility potential. Early blocks t o embryo development in in vitro conditions, as compared to in vivo su ccess, means that critical developments during the first cell cycles o f embryonic life in the oviduct are actively regulated by oviductal em bryotrophic factors. These have been used clinically in co-culture sys tems. Lytic factors are weak in human other primates, predisposing to high incidence of tubal pregnancies, with considerable impact on medic al practice. Diverse oviductal factors affect the incidence, infection being the most significant. Optimal oviductal function is neccessary to provide a proper environment for early human life.