In vitro fertilization (IVF) was designed to help women with fallopian tube blockage or structural damage – known as tubal factor infertility – which accounts for as much as a 25-30% of all infertility cases. Corrective tubal surgery was not very successful if there was severe tubal damage from prior infections, endometriosis, or scar tissue from prior surgeries. Frequently in these cases, the ovaries, eggs, sperm, and uterus were normal, but without a functioning fallopian tube (or tubes), the gametes could not meet and form embryos. IVF took fertilization out of the bedroom and into the laboratory – more than 35 years and five million babies later, the process has answered many parents’ prayers.
Once fertilization could be done in the laboratory, procreating was no longer synonymous with intimacy and sexuality. This has allowed third party reproduction to be possible. From the first successful egg donation in 1983 through to today, Assisted Reproductive Technology (ART) has become hugely successful.
The process of egg donation is fascinating. First, the donor takes fertility medications to ensure multiple follicle (egg) development. During this stimulation, she makes frequent visit to the reproductive medicine office to monitor the growth of her follicles and estrogen production. Simultaneously, the parent-to-be (know as the oocyte recipient) takes estradiol to prepare her uterus for implantation.
The process kicks into high gear in the middle of the donor’s cycle when ovulation is triggered by the application of an injectable hormone. Thirty-six hours later, the follicles are aspirated via a needle attached to a vaginal probe ultrasound. Later that same day, the eggs and sperm are mixed together either with conventional IVF where sperm are overlaid on top of the eggs or via intracytoplasmic sperm injections (ICSI), when the sperm head is injected by needle directly into the egg. (ICSI is used for men with abnormal semen parameters or for couples who have never had any conception or prior natural fertilization.) Five days later, an embryo is implanted into the uterus of the oocyte recipient after adding progesterone to her estrogen regimen.
Egg donors go through a rigorous screening process. Egg donors have tests to ensure that they have no sexually transmitted diseases or infections. They are also screened for drug use. In addition, their medical and family history is reviewed. Genetic tests are often done to make sure that they do not carry gene mutations that might lead to children with specific disorders. Finally, donors are also required to have psychological screening.
Egg donation opened up fertility to many women. Older women whose ovaries no longer make quality eggs – even those who are in menopause! – are now able to conceive. Younger women who have gone through an early menopause (i.e., due to surgical removal of their ovaries from chemotherapy or unknown causes) can now get pregnant and carry a baby to term. Genetically, these babies do not have their intended mother’s DNA, but they do have their father’s DNA.
Egg donation success rates are better than standard IVF, with pregnancy rates per cycle often as high as 60% per stimulation. Moreover, young egg donors frequently make many eggs, and often yield multiple embryos – thus after one stimulation, several attempts at conception are possible. Frequently there are surplus embryos that may never be used.
Recently, using a newer technique called vitrification, the ability to freeze eggs is now possible and successful. For years past, egg donation required the synchronization of two women’s cycles. Optimal success was achieved with fresh embryo transfer less than a week after oocyte retrieval. With vitrification, the embryologists can now freeze egg donor’s eggs and store them in egg banks. Very soon, there will be egg banks similar to sperm banks, and the collection of eggs will be separated from the recipient’s transfer cycle. The recipient will be able to choose six eggs from a single donor. The eggs will then be thawed and inseminated prior to transfer. Over time, this may prevent the production of numerous surplus embryos without compromising success rates.
Young women now can consider the prospect of freezing their eggs to ensure that if someday they need an egg donor, they can use their own stored eggs. Many women are considering egg freezing (check out The Pros of Fertility Preservation and The Cons of Fertility Preservation), but most who consider it are already in their mid to late 30s. Now that egg freezing is a reality, more young women in their mid 20s may want to consider one cycle of egg freezing as an insurance policy against unforeseen circumstances. These same women would make excellent egg donors. It may even be possible to combine a cycle as an egg donor and also as a personal egg freeze.
For more information about this combination cycle, CONTACT US.