A couple’s success with fertility treatments primarily depends on the female partner’s fertility, since male-factor infertility can be remedied in almost all cases via intracytoplasmic sperm injection, ICSI. Donor egg cycles, therefore, can be presumed to fail for, principally, the same reasons why all IVF cycles fail: either the quality of eggs/embryos is sub-par, and/or the implantation process does not function properly. In the latter case (the implantation process is still a “black box”), the reason, again, may lie with the egg/embryo or with the uterus and/or the maternal immune system. Because egg donors are usually very young, their eggs have high pregnancy potential but, even in 20-year-old egg donors, not all eggs are perfect, and the same, therefore, applies to the embryos made with those eggs. This is one reason why egg donor selection is of such crucial importance, as we noted here when discussing sources of donor eggs.
There are, of course, better and poorer IVF programs but donor egg recipient cycles uniformly achieve the highest pregnancy and live birth rates among all IVF cycles, whatever the constellation of contributions may be. Outcomes also depend on clinical factors: Though it is true that maternal age does not matter much when it comes to egg donation, conception rates are, still, declining to some degrees with advancing female age. In addition, pregnancy and live birth rates vary whether one or two embryos are transferred (IVF centers only rarely transfer more than 2 embryos in donor-recipient cycles). Obviously older women are often not well suited to carry twins and, therefore, will be mostly treated with elective single embryo transfers and, therefore, will encounter lower pregnancy rates for that reason alone.
The important thing to remember for patients who fail a donor recipient cycle is that they, more often than not, will still have embryos cryopreserved. Since these embryos come from “young” eggs, their pregnancy chances are very good, indeed only ca. 10% lower than in fresh transfers. In other words, especially if patients receive only one embryo at a time, it is important to remember that even when embryos are produced from young and carefully selected donor eggs, not all of these embryos have the potential to lead to pregnancy and it may take more than one transfer to be successful.
This is a part of October 2018 CHR VOICE.
Norbert Gleicher, MD, leads CHR’s clinical and research efforts as Medical Director and Chief Scientist. A world-renowned specialist in reproductive endocrinology, Dr. Gleicher has published hundreds of peer-reviewed papers and lectured globally while keeping an active clinical career focused on ovarian aging, immunological issues and other difficult cases of infertility.
DISCOVER YOUR TREATMENT OPTIONS
