Getting Pregnant with Donor Gametes
A donor egg or banked sperm may be the best route to conception for some couples
There are some women who are simply unable to produce any eggs. This may be a result of prior surgery with removal of the ovaries or prior cancer treatments such as radiation therapy or chemotherapy, which can render the ovaries nonfunctional. There are also a surprising number of women who undergo “premature ovarian failure.” It must be remembered that all of the eggs a woman has she is born with—no new eggs are ever produced. It is believed that some women are born with fewer eggs than normal and that there are other women who use up their eggs more quickly than normal.
There may be other factors involved also, but the point is that some women may reach menopause in their thirties or even in their twenties or earlier. When a woman reaches menopause, there are not any functional eggs left in the ovaries.
There are also a couple of other indications for the use of donor eggs. Women who carry a gene for certain disease processes, or who have abnormal chromosomes themselves may need donor eggs to allow a successful, normal conception. Finally, an ever-increasing number of women are delaying their attempts at conception until they are older.
Successful conception until age 40 and beyond is certainly possible. However, the older a woman is, the more difficult it typically becomes because of the effect of aging on the number and the quality of the eggs remaining in the ovaries. When efforts to conceive using their own oocytes fail for these women, the use of donor oocytes can restore their fertility potential to that of a much younger woman. There is excellent evidence that far and away the most important factor accounting for the age-related decrease in fertility is the decrease in the functional potential of the eggs. The uterus and the rest of the reproductive organs maintain their capacity to establish and carry a pregnancy until menopause and beyond.
At the current time, there are no “egg banks” like there are for sperm. This is because the technology that will allow the freezing and later use of eggs has not been developed. Eggs are very difficult cells to preserve through the freezing process, and the rate of success with this is so low that fresh eggs must be used in any attempt. Secondly, eggs are not nearly as easy to obtain as are sperm. An egg donor must undergo the relatively complex process of ovarian stimulation and egg retrieval. The use of donor eggs is, therefore, much more complex than is the use of donor sperm.
Potential egg donors are recruited by advertising or word of mouth. Any individual expressing an interest in being an egg donor must undergo the following screening and meet the following criteria:
1. We prefer donors between the ages of 25 and 30, although donors up to age 35 are accepted if they have proven fertility. Although some programs allow college-aged women to be donors, we do not generally feel this is appropriate.
2. A very careful family and medical history is obtained. A strong family history of inheritable conditions such as heart disease, breast cancer, or alcoholism, for example, exclude an individual. A history of significant medical problems in the donor herself will also eliminate her from consideration as donor.
3. Donors are screened for infectious processes such as HIV, syphilis, hepatitis, gonorrhea, chlamydia, and herpes. Because donor eggs must be used “fresh,” quarantining like that done for donor sperm is not possible. Potential donors are, therefore, carefully questioned about their sexual activity. If they have had more than one sexual partner in the last six months they are excluded. Similarly, if they have any history of intravenous drug use or other high risk behavior they are excluded. While this does not offer 100 percent protection against infection transmission, donors are by definition from a very low risk population and the risk of transmission of disease is extremely low.
4. All potential donors undergo careful psychological screening and evaluation, and standardized psychological profile testing.Their motivation is carefully evaluated. We have found that altruistic individuals make excellent egg donors while individuals whose primary interest is compensation are poor candidates.
The matching of donor and recipient can be done in many different ways. We have the recipient couple complete a “recipient profile.” This details what characteristics and traits are most important to that couple. We also include a picture of the couple on this form, as well as their blood types. When a donor becomes available, she is “matched” to a couple by a panel of three individuals composed of the nurse and physician in charge of the donor egg program, as well as the psychological counselor. The recipient couple is then provided with nonidentifying information about the donor and certainly has the right to reject any donor. Anonymity, however, is maintained. The donor is never identified to the recipients, and the donor relinquishes all rights to pursue the identity of the recipients.
Potential recipients must also undergo health and psychological screening. Particularly for older women, careful health screening including an EKG, chest X-ray, blood screening, and general medical evaluation may be indicated. All couples requesting the use of donor eggs must undergo counseling and psychological evaluation of their preparedness for this procedure.
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