Pacific Fertility Center takes great pride in its pregnancy success rates resulting from oocyte donations to women who are unable to provide their own high-quality eggs. An oocyte donation procedure involves much more than screening and scheduling. Both the donor and the recipient’s bodies have to be “synchronized” carefully and deliberately, matching the donor’s oocytes to the recipient’s uterus, as if there were one body making the egg and growing the embryo. This article describes the synchronization steps that match the oocyte to the uterus.

After all parties have completed the required screening, the donor and recipient are typically started on low-dose oral contraceptive pills. While the menstrual cycles of donor and recipient may begin on different days, the pills cause the ensuing menstrual flows to match. Depending on how far apart their menstrual cycles occur, it can take up to two weeks for their respective cycles to be synchronized. Additionally, the pills help prevent the women from developing ovarian cysts, fluid sacs in the ovary, which can delay the start of the cycle.

After a minimum time of at least 14 days of the pill a medication called “Lupron” or “Synarel” is prescribed for both parties. These medications turn off the fertility hormones produced by the pituitary gland and, in essence, shut down the ovaries. Lupron is taken as a subcutaneous injection. Synarel is administered as a nasal spray. Once it is determined that both women’s pituitary glands are adequately suppressed, stimulation of the donor’s ovaries and the recipient’s endometrium may be initiated respectively. Both donor and recipient continue with Lupron injections or Synarel sprays to help prevent early ovulation.

As the donor is initiating stimulation of her ovaries, the recipient starts taking estrogen to prepare the endometrium or uterine lining. The lining is very thin after the menstrual flow. Estrogen stimulates the thickening and development of the lining in preparation for implantation of the future embryo. In a natural cycle, estrogen comes from the follicle developing in the ovary. Since the recipient’s ovaries are suppressed, the estrogen comes from medication. An ultrasound will determine the thickness of the uterine lining and some supplementation may be administered to ensure the best possible environment for implantation. She will have between 10 days and two weeks before the implantation.

High tech methods of administering estrogen have been developed. Pure estradiol is very similar to cholesterol, and is very poorly absorbed when taken orally. Injectable estradiol is closest to natural estrogen. It is most easily administered in an oil base, as estradiol valerate. Small amounts of estrogen can also be given through a patch, since estradiol can be absorbed through the skin. Vivelle and Estraderm are examples of estrogen patches. While oral estrogen is not easily absorbed, special manufacturing tricks can improve absorption. Estrace is a pill form in which the estradiol is specially manufactured in microcrystals that have a higher surface area to improve absorption through the intestinal tract.

The donor will begin intramuscular injections of fertility medications that gradually stimulate the growth of numerous follicles on her ovaries. This process is known as controlled ovarian hyperstimulation.

While the donor is administering the fertility medications, she begins to be monitored by routine blood tests that determine estradiol levels to monitor the development of the follicles.

At the same time, the recipient is being monitored by periodic estradiol levels and ultrasound evaluations for endometrial thickness.

After five to seven days of stimulation the donor’s follicles are measured. In a typical stimulation, both the left and right ovaries reveal multiple maturing follicles. Ideally the eggs mature at the same rate so they are all about the same size and have similar capacity to be fertilized.

When the physician determines the optimal timing of the egg retrieval, the donor will receive a final injection called hCG, which will mature the eggs for retrieval.

On the morning of egg retrieval, the male finally comes into play. Ideally a fresh collection of sperm by the recipient’s male partner or sperm donor is produced to fertilize the retrieved eggs. A masturbated sperm sample is enhanced by a highly specialized process prior to being placed with the eggs, generally involving washing of the sperm to remove the less viable ones.

Approximately 72 hours following ovum retrieval, selected embryo(s) are transferred to the recipient’s uterus. If there are embryos of sufficient quality remaining, they may be cryopreserved for subsequent transfers.

The embryo transfer procedure into the recipient usually requires no anesthesia. A catheter is inserted through the cervix into the uterus, and the embryos are gently and carefully placed into the uterine cavity. The recipient is maintained in a recumbent position for approximately five minutes and then discharged. The recipient will need to take daily progesterone hormone injections in order to sustain an optimal environment for the embryo implantation. This post-implantation or post embryo transfer time is called the luteal phase. Ideally, the embryo begins developing and implants in the lining of the uterus.

Approximately two weeks after the embryo transfer a pregnancy test is performed. If the pregnancy test is negative, all hormonal treatments are discontinued and menstruation will usually ensue within two weeks. If the Beta-hCG titer is rising, as determined by a second test, this indicates that implantation has taken place. Hormone injections will then be continued until 12 weeks of gestation at which time the placenta will supply all the hormones necessary to sustain the pregnancy. In the interim, ultrasound examination(s) will be performed to definitively diagnose pregnancy between 5 to 6 weeks after the embryo transfer.

The donor by this time will begin to return to her regular cycle, and will most likely have her period about 10 days after retrieval.

– Philip E. Chenette, MD

Tags: Egg Donation, Female Infertility, IVF - In Vitro Fertilization, Medications

This entry was posted on Monday, February 6th, 2006 at 6:43 pm and is filed under Science Pulse. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.