The Medical Process of Gestational Surrogacy

Ovarian/Follicular Stimulation and Donor Monitoring

Typically, women only ovulate one egg per menstrual cycle. In order to increase the chances of a viable pregnancy, multiple eggs are required so that more than one embryo can be transferred to the uterus of a surrogate. In order to increase the number of mature eggs produced, it is necessary to stimulate the intended mother’s ovaries with fertilizing agents called gonadotropins.

Approximately seven days after ovulation in the cycle preceding the stimulation of the intended mother’s ovaries, daily injections of Lupron are administered to the intended mother to regulate her pituitary gland’s production of follicle-stimulating hormones (FSH) and luteinizing hormones (LH). With the onset of menstruation approximately seven to ten days later, a baseline ultrasound examination is performed to ascertain that no ovarian cysts are present. At that time, a decision is made regarding when gonadotropins therapy (Fertinex, Follistim, Gonal-F, Pergonal and/or Humegon) should commence.

The first day of gonadotropin therapy is referred to as Cycle Day 2. Five days later, on Cycle Day 7, monitoring through hormone (estradiol) measurements and ultrasound examinations begins. Typically,
one to three additional days of gonadotropin therapy will be required. Once optimum follicular
development is confirmed, ovulatory trigger human Chorionic Gonadotropin (hCG), is administered
by injection. The eggs are then harvested via transvaginal ultrasound-guided aspiration 36 hours
after the hCG injections are administered in order to ensure they are captured prior to ovulation.

Cycle Synchronization

The surrogate begins Lupron injections during the preceding cycle, while the intended mother is
undergoing follicular stimulation. The duration of this therapy is adjusted to synchronize her cycle
with that of the intended mother. Once the intended mother begins the process of follicular stimulation,
the surrogate begins to receive estradiol valerate injections while continuing to receive Lupron.

Preparing the Surrogate’s Uterine Lining

Estradiol valerate is injected on Tuesdays and Fridays. The surrogate’s blood is drawn on Mondays and Thursdays to measure serum estradiol concentrations, the levels of which determine the amount of
necessary subsequent hormone doses. An ultrasound examination is performed ten days to two weeks
after the surrogate begins the estradiol valerate injections to determine when her endometrial lining is
optimal. The intended mother, who is undergoing follicular stimulation, will be given the option of having her eggs harvested, fertilized and stored in a frozen state (cryopreserved) for transfer to the surrogate’s uterus in a subsequent cycle.

Approximately four days prior to the anticipated embryo transfer, the surrogate receives daily injections of progesterone in order to optimize preparation of the surrogate’s endometrium for implantation.

Egg Retrieval

In the next cycle, the intended mother’s eggs are retrieved via transvaginal ultrasound-guided aspiration. This procedure is low-risk and relatively painless. A needle is passed through the vagina and into the ovaries, and the follicular fluid and oocyte are aspirated from each follicle. The egg retrieval is performed with the aid of intravenous sedation and takes approximately twenty minutes. The patient can usually return to her normal activity level in six to twelve hours.

Fertilization and Embryo Culture

Eggs removed from the ovaries are immediately examined and graded. They are then placed in a culture medium in preparation for fertilization. After subjecting the sperm to a highly specialized preparation and enhancement process, each egg is inseminated with about 50,000 sperm and the incubation process begins. Sixteen to 20 hours later, the eggs are inspected for evidence of fertilization.

Embryo Transfer

About 72 hours after the eggs are retrieved from the intended mother, the embryos are transferred to the surrogate’s uterus. After this transfer the surrogate must lie still for one to one-and-a-half hours. She
is then discharged and instructed to limit her activity and relax at home for the next three days.

Follow-up

After the embryo transfer, the surrogate receives daily hormone injections so that her body will
sustain an optimal environment for the newly inseminated embryos. A blood test is performed
to ascertain pregnancy eight to ten days after the embryo transfer. If the test is positive, an
ultrasound examination is scheduled for approximately 18 days later. Hormone injections
will be continued for an additional eight weeks. If the cycle proves unsuccessful, all treatments
are discontinued. Menstruation then usually begins within seven days. At that time, the
intended mother may elect to have her frozen embryos thawed and transferred to the
surrogate at a later date.

Information provided by the Northern California Fertility Medical Center.