Evaluating Prospective Egg Donor Candidates
1. Donor History
Appropriate and careful history taking is essential in order to identify any personal or family history that might point towards potential medical problems that might arise during or after the cycle of stimulation and the egg retrieval. Systemic disease, allergies to known medications, hemorrhagic diatheses and mental disease are but a few significant examples. It is also extremely important to try and rule out potentially debilitating hereditary and chromosomal disorders that could affect the quality of any offspring arising out of the egg donation.
Most programs in the United States follow the American Society of Reproductive Medicine's (ASRM) recommendations and guidelines for selective genetic screening of prospective egg donors for conditions such as sickle cell trait or disease, thallasemia, cystic fibrosis and Tay Sachs disease, when medically indicated. Consultation with a geneticist is available in about 90% of programs. There are, however, still a significant number of OD ART-programs in the United States that do not follow all ASRM guidelines.
Most American recipient couples place a great deal of importance on emotional, physical, ethnic, cultural and religious compatibility with their chosen egg donor. In fact, they will often insist that the egg donor's sexual orientation be heterosexual.
2. Psychological Screening
Americans tend to place great emphasis on psychological screening of egg donors. Since most donors are "anonymous", it is incumbent upon the OD agency or ART program to determine the donor's degree of commitment as well as her motivation for deciding to provide this service. We have on occasions encountered donors who have buckled under the stress and defaulted mid-stream during their cycle of stimulation with gonadotropins. In one case, a donor knowingly stopped administering gonadotropins without informing anyone. She simply awaited cancellation, which was effected when follicles stopped growing and her plasma E2 concentration failed to rise.
Such concerns mandate that assessment of donor motivation and commitment be given appropriate priority. Most recipients in this country tend to be very much influenced by the "character" of the prospective egg donor, believing that a flawed character is likely to be carried over genetically to the offspring. In reality, unlike certain psychoses such as schizophrenia or bipolar disorders, character flaws are usually neuroses and are most likely determined by environmental factors associated with upbringing. As a result, they are unlikely to be genetically transmitted. Nevertheless, all donors should be subjected to counseling and screening, and should be selectively tested by a qualified psychologist. When in doubt they should be referred to a psychiatrist for definitive diagnosis. Selective use of tests such as the MMPI, Meyers-Briggs and NEO-Personality Indicator are used to help screen for personality disorders. Significant abnormalities, once detected, should lead to the automatic disqualification of such prospective donors.
When it comes to choosing a known donor, it is equally important to make sure that she was not coerced into participating. We try to caution recipients who are considering having a close friend or family member serve as their designated egg donor that in doing so, the potential always exists that the donor might become a permanent and unwanted participant in the lives of their new family.
3. Assessing for Substance Abuse
We typically use urine and/or serum drug testing of egg donors. This is to minimize the risk to our recipients of an undiagnosed but significant risk factor.
4. Assessing the Donor's Ovarian Responsiveness
Assessing an individual's follicle recruitment potential is accomplished by measuring FSH and E2 on the 3rd day of a spontaneous menstrual cycle. In addition to these tests, we also measure the woman's serum Inhibin-B levels. An FSH of less than 8.0 mIU/ml in association with a plasma estradiol concentration between 20 and 60 pg/ml and an Inhibin-B level above 45 ng/ml on CD3 usually points to the woman being a potentially good responder to gonadotropin stimulation. However, recipients must be made aware of the possibility of a suboptimal ovarian response in spite of these tests all being within normal limits. Other measurable hormonal parameters include Thyroid Stimulating Hormone (TSH), free T4 and prolactin, which if present in a high concentration, can competitively bind with granulosa cell FSH receptors, reducing ovarian response to gonadotropins.
5. Testing for Sexually Transmittable Diseases
FDA guidelines require that all egg donors be tested for sexually transmittable diseases before entering into a cycle of IVF. It is highly improbable that DNA and RNA viruses are vertically transmitted to an egg or an embryo through sexual intercourse or IVF. Nevertheless, the albeit remote possibility of transmission and the associated legal ramifications demand that potential donors so infected be disqualified from participating in IVF with egg donation. For example, it is easily conceivable that the egg donation process could be blamed for an unrelated occurrence of disease states such as hepatitis b, c or HIV. In addition, evidence of prior or existing infection with Chlamydia or gonorrhea introduces the possibility that the egg donor so affected might have pelvic adhesions or even irreparably damaged fallopian tubes that might have rendered her infertile. Even if an egg donor or recipient who carries a sexually transmittable viral or bacterial agent is willing to waive all rights of legal recourse, a potential risk still exists that a subsequently affected offspring might in later life sue for wrongful birth.
6. Medical Evaluation
While advancing age beyond 40 years is indeed associated with an escalating incidence of pregnancy complications, such risks are largely predicable through careful medical assessment prior to pregnancy. The fundamental goal is to determine that the recipient is capable of safely carrying a pregnancy that would culminate in the safe birth of a healthy baby. For this reason, a thorough evaluation must be done prior to initiating IVF in all cases.
7. Infectious Screening
The need for careful infectious screening for embryo recipients cannot be overemphasized. Aside from tests for debilitating and life-threatening sexually transmittable diseases, there is the important requirement that cervical mucus and semen be free of infection with ureaplasma urealyticum. This organism, which rarely causes symptoms, frequents the cervical glands of 15-20% of women in the United States. The introduction of an embryo transfer catheter via an infected cervix might easily transmit the organism into an otherwise sterile uterine cavity. Ureaplasma and Mycoplasma induce apoptosis of trophoblast cells, leading to early implantation failure and/or first trimester miscarriage.
