Transfer and uterine factors are the major recipient-related predictors of success with donor eggs

Abstract

Background: Ovum donation has the highest success rate of all assisted reproductive technologies, yet only 41.6% of the 5,844 fresh donor egg transfers reported to the CDC in 1999 resulted in a live birth. The causes of failure have proven difficult to study because of the heterogeneity of donors, recipients, and programs.Objective: To define recipient-related variables affecting the outcome of donor egg cycles by keeping the oocyte and laboratory components constant.Materials and Methods: The subjects consisted of 116 infertile women who underwent 134 donor egg cycles in which two recipients shared eggs from a single, young, fertile, compensated, anonymous donor. The variables examined included: age, body mass index, gravidity, preexisting medical conditions, endometriosis, uterine pathology, endometrial thickness, male factor, the use of ICSI, number of eggs, fertilization rate, number of embryos, embryo quality, number of fresh embryos per transfer, number of embryos frozen, difficulty of transfer, and the ongoing pregnancy rate.Results: Out of the 67 recipient pairs, the subgroup of 41 pairs with discordant outcomes was the primary focus of analysis. Within this subgroup, non-pregnant subjects had higher frequency (31.7% v 9.7%, P = 0.04) and greater severity of uterine pathology than the pregnant controls. Non-pregnant women were more likely to have either moderate or difficult embryo transfers (31.7% v 9.7%, P = 0.04). Whereas the mean endometrial thickness did not differ, 6 of 41 non-pregnant patients (14.5%), but none of the pregnant subjects, had endometrium < 8 mm (P = 0.01). In the non-pregnant group, at least one of the above three factors was present in 56.1% of cycles compared to only 19.5% of transfers in the pregnant group (P = 0.001). None of the remaining variables differed between the groups.Conclusion: Analysis of discordant recipient pairs permits the definition of recipient-related determinants of success by assuring that quality of the eggs and of the laboratory are both constant and adequate for conception. Uterine pathology, embryo transfer, and thin endometrium appear to be the main recipient-related variables resulting in failure to establish pregnancy with donor eggs. Background: Ovum donation has the highest success rate of all assisted reproductive technologies, yet only 41.6% of the 5,844 fresh donor egg transfers reported to the CDC in 1999 resulted in a live birth. The causes of failure have proven difficult to study because of the heterogeneity of donors, recipients, and programs. Objective: To define recipient-related variables affecting the outcome of donor egg cycles by keeping the oocyte and laboratory components constant. Materials and Methods: The subjects consisted of 116 infertile women who underwent 134 donor egg cycles in which two recipients shared eggs from a single, young, fertile, compensated, anonymous donor. The variables examined included: age, body mass index, gravidity, preexisting medical conditions, endometriosis, uterine pathology, endometrial thickness, male factor, the use of ICSI, number of eggs, fertilization rate, number of embryos, embryo quality, number of fresh embryos per transfer, number of embryos frozen, difficulty of transfer, and the ongoing pregnancy rate. Results: Out of the 67 recipient pairs, the subgroup of 41 pairs with discordant outcomes was the primary focus of analysis. Within this subgroup, non-pregnant subjects had higher frequency (31.7% v 9.7%, P = 0.04) and greater severity of uterine pathology than the pregnant controls. Non-pregnant women were more likely to have either moderate or difficult embryo transfers (31.7% v 9.7%, P = 0.04). Whereas the mean endometrial thickness did not differ, 6 of 41 non-pregnant patients (14.5%), but none of the pregnant subjects, had endometrium < 8 mm (P = 0.01). In the non-pregnant group, at least one of the above three factors was present in 56.1% of cycles compared to only 19.5% of transfers in the pregnant group (P = 0.001). None of the remaining variables differed between the groups. Conclusion: Analysis of discordant recipient pairs permits the definition of recipient-related determinants of success by assuring that quality of the eggs and of the laboratory are both constant and adequate for conception. Uterine pathology, embryo transfer, and thin endometrium appear to be the main recipient-related variables resulting in failure to establish pregnancy with donor eggs.