Thursday, March 28, 2024
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Donor Oocytes

In recent years, with the standardization of IVF-ET techniques and the development of ICSI (intracytoplasmic sperm injection) for severe sperm disorders, it has become clear that the single most important factor in predicting the success of IVF-ET is the age of the female partner. For patients under 30, success rates of 30-50% per oocyte retrieval can legitimately be expected; for patients over 40, realistic success rates are only usually less than 10%. Oocytes from younger women possess greater fertility potential, and this potential is utilized in donor oocyte treatment. In this situation, oocytes from another woman (the donor) are fertilized with the patient’s (the recipient) husband’s sperm, and the resultant embryos are placed in the recipient’s uterus. The oocytes are stimulated and retrieved from the donor using routine IVF-ET techniques. The donor may be known to and recruited by the recipient (non-anonymous donation), or instead may be unknown to the recipient, having been recruited by the IVF-ET program (anonymous donation) or by a donor egg agency. Anonymous oocyte donation usually occurs when a young, fertile woman donates all of her oocytes to a recipient during a particular cycle. This woman is not trying to achieve pregnancy and will therefore be reimbursed for her time and effort. In this case the recipient is responsible for all prerequisite costs for the oocyte donor as well as the cycle. Each recipient couple must decide the type of donor with whom they are most comfortable.

Candidates for Donor Oocyte
There are four main indications for the need of donor oocyte.: 1) ovarian failure. This can be due to a wide variety of different causes, including radiation, chemotherapy, surgical removal of the ovaries and a variety of disease states which cause or are associated with ovarian failure; 2) women who carry some serious genetic disease who wish to diminish the chance that the disease will be passed on to their offspring; 3) women whose age is sufficiently advanced so that their fertility potential is impaired significantly; abd 4) women who have had poor quality embryos during previous IVF cycles.

Laboratory Testing, Genetic Screening, and Psychological Assessment
A short time before initiating a treatment cycle, the oocyte donor undergoes a very thorough battery of tests for sexually transmitted infections. Obviously, by screening for sexually transmitted infections, we seek to minimize the chances that such a infection will be passed from the donor to the recipient (and possible fetus) by the oocyte donation process. Despite these thorough precautions, a very small risk of transmission of infections from donor to recipient remains. In addition to sexually transmitted infection testing, the donor’s blood type will be determined. The donor’s blood type may be a factor in making the match between donor and recipient (see below).

All donors have a very thorough evaluation of their medical, psychological, and family history. The donor is required to fill out a multi-page form detailing her family history. The IVF personnel and a genetic counselor for the oocyte donation program review this form and other aspects of the donor’s genetic and medical history prior to acceptance of the donor into the program. The genetic counselor sometimes recommends additional testing for the donor. Even with this intensive screening, there remains a small risk that a baby resulting from the oocyte donation process will suffer from a genetic disease. Overall, a baby conceived through oocyte donation will have the same risk of birth defect, small or large, genetic or nongenetic, as the human population as a whole, namely 3-5%. The donor should also receive psychological screening and counseling with a mental health professional to assess her motivations and ability to follow through in the process. This evaluation serves as an additional opportunity to learn about family and medical history which may affect her acceptance as a donor.

Matching Donor and Recipient
We understand that choosing to receive donated oocytes carries with it a simultaneous sacrifice of hope for pregnancy with one’s own oocytes, and this can be a feeling of great loss. There are probably many characteristics that you hope your oocyte donor will possess, and you probably desire that your oocyte donor will possess many of your own characteristics. The IVF team do what it can to assist you in selecting a donor who meets your most important expectations, but you must understand that we will always face certain limitations. One requirement of most anonymous donation program is that anonymity be maintained. In order to accomplish this, we are limited in the amount of information that we can give you about the donor. We cannot tell you much more than donor’s height and weight, hair color and eye color, race, blood type, age and duration of formal education. We also give you as much family medical history as we know. You have the right to be as specific as you like about the characteristics of the donor, but you need to understand that the more specific you are, the longer the entire process may be delayed. Studies indicate that women who agree to donate their oocytes tend to be upbeat, energetic, resilient and altruistic. If they did not have these personality characteristics, they probably would not be willing to undergo the discomfort and risks involved in oocyte donation and IVF in the first place. Thus, to at least a small extent, the process of oocyte donation tends to select from women with these favorable personality characteristics. Some donors are women who are attempting conception through IVF themselves.

Treatment of the Oocyte Donor
In general, stimulation of the oocyte donor’s cycle is brought about using a similar regimen of drugs that a woman using her own oocytes for in vitro fertilization-embryo transfer is commonly given. Late in the cycle which precedes ovarian stimulation, the donor is started on daily treatment with one of two drugs, Lupron® or Synarel®, usually the former. Daily injections of Lupron® will continue for a total of nearly three weeks. After the donor’s period has started, daily intramuscular injections of a pharmaceutical gonadotropin preparation, such as FSH and HMG, will be added to the daily Lupron® injections. Various brands of these hormones can be used. Generally, the donor will receive daily gonadotropin injections for a total of seven to twelve days. During the time that the donor is receiving the gonadotropin injections, she will have frequent vaginal ultrasound examinations and blood drawing for determination of estradiol (E2) level. When ultrasound and blood testing indicate that development of the follicles (follicles are the ovarian structures that contain the oocytes) is optimum, the donor receives an intramuscular injection of a different pharmaceutical medication called human chorionic gonadotropin (hCG). Approximately 32-36 hours after hCG injection, oocyte retrieval is performed. We will need a sperm specimen from the recipient’s partner on the day of the retrieval, because the oocytes are inseminated on this day. Transfer of fertilized eggs (embryos) to the recipient’s uterus is generally performed three days after the oocyte retrieval. Sometimes embryo transfer is delayed until five days after oocyte retrieval, based upon recommendations by the embryologist and physician team.

Treatment Regimen for Recipients
In general, we try to arrange for recipients to have a "fresh" as opposed to frozen embryo transfer. In order to do this, the recipient’s cycle must be manipulated to synchronize her with the donor. A combination of two or three hormonal medications is used to modify the recipient’s cycle.

Recipients who have regular menstrual cycles and bleeding on their own will take a medication which suppresses their own cycle. Sometimes oral contraceptives will be used to precede Lupron® or Synarel® administration. A few days before the recipient’s period is expected to start, she is started on Lupron® to suppress her natural cycle. A short time after her period starts the recipient will begin taking estrogen in addition to the Lupron®. When the donor’s cycle has “caught up” with the recipient’s, a simulated (artificial) 28 day menstrual cycle will be created in the recipient with the hormonal medications. We perform blood tests for hormone levels and/or an ultrasound as oocyte retrieval approaches to ensure an appropriate response. Lupron® treatment will continue throughout this time. On the morning after oocyte retrieval, progesterone treatment is begun. Progesterone is given usually as a daily intramuscular injection of a preparation of progesterone in oil. The day before embryo transfer, Lupron® is discontinued. The recipient will continue taking Vivelle® and progesterone at least until the day her pregnancy test is performed. Fresh embryo transfer will be performed 3-5 days after oocyte retrieval. A sensitive blood pregnancy test will be performed on the 10th day after embryo transfer. If the recipient is pregnant, patches and progesterone treatment will be continued through the twelfth week of pregnancy.

Gestational Carriers
In some instances a couple may require the assistance of a gestational carrier to achieve a successful pregnancy. Gestational carriers differ from true surrogates in that they have no genetic link to the baby they will carry. The commissioning couple themselves will provide the embryo through IVF. As with oocyte donation, the best statistics occur when the embryos are transferred during a fresh cycle, requiring that the women and her gestational surrogate be synchronized as with oocyte donation. Some states have laws that address surrogacy and you should seek legal advice about this. For example, Florida law requires that a woman have a medical indication for a gestational carrier to be utilized. The most common indications include a woman who has congenital absence of the uterus, prior surgery to remove her uterus, severe scarring of the uterine cavity, or a medical history that precludes pregnancy. In addition to meeting the medical requirement, a separate legal contract is required before treatment can begin. In Texas, in order for the carrier not to be identified as the legal mother, the surrogacy arrangement must be reviewed and approved by a judge before treatment begins. Programs may or may not have ready access to a group of potential gestational carriers. Generally, however, they can provide resources for investigation. Once a gestational carrier has been identified and the medical, psychological, and legal prerequisites completed, treatment can proceed.