GAMETE INTRAFALLOPIAN TRANSFER - OUTCOME FOLLOWING THE ELECTIVE OR NON-ELECTIVE REPLACEMENT OF 2, 3 OR 4 OOCYTES

The outcome of 807 gamete intra-Fallopian transfer (GIFT) cycles follo wing the elective or non-elective transfer of two, three or four oocyt es has been retrospectively studied. Electively replacing either three or two oocytes did not reduce the clinical or ongoing pregnancy rate when compared with replacing four oocytes. The incidence of high-order multiple gestation (triplet or more) was significantly reduced by rep lacing fewer oocytes, but the occurrence of twin pregnancy was not alt ered. Lower pregnancy rates were found when the number of oocytes avai lable for replacement was limited and non-elective replacement was per formed. It is suggested, therefore, that a higher number of oocytes av ailable may allow selection of higher quality oocytes for transfer. We conclude that the overall expectation of pregnancy from the GIFT proc edure is high (30-40%) and the number of oocytes replaced should be tw o in order to minimize the risk of high-order multiple pregnancies. It is not clear whether increasing the number of oocytes transferred wil l benefit subjects who failed to become pregnant previously with GIFT, but limited data suggest that transferring large numbers of oocytes t o women >40 years does not improve the expectation of pregnancy.