Gestational Surrogacy Process
The gestational surrogacy process is separated in two ways
- Selecting and Screening Surrogates
- Controlled Ovarian Stimulation of the Egg Provider
COH is used to maximize the number of retrievable eggs for fertilization. The goal is to optimize the chances of a viable pregnancy. For women that do not have menstrual cycles (due to hysterectomy or endometrial resection), approximately 14 days after spontaneous ovulation occurs (as assessed by home ovulation test kit), she starts taking a birth control pill (BCP). About 8 to 20 days later a GnRHa is administered daily to prepare the ovaries. After 5 days of GnRHa, the BCP is stopped and the woman providing the eggs continues on the GnRHa for another few days, at which time daily blood estradiol (E2) measurements are done. Once the E2 is found to be less than 70pg/ml, the she is ready to receive gonadotropins. The exact timing is dependent upon when the surrogate (whose cycle has been synchronized) starts menstruating and reaches an E2 level of less than 70 pg/ml as well.
The female partner’s first day of gonadotropin injections is referred to as cycle day 2. On cycle day 9, the program would likely begin intensive daily monitoring by means of blood hormone measurements and ultrasound examinations. Usually, one-to-three additional days of gonadotropin therapy will be required. Once monitoring confirms that the female partner’s ovarian follicles have developed optimally, she is given an injection of the ovulatory trigger, hCG, at which time daily injections of GnRHa are discontinued. Her eggs are retrieved 34 to 36 hours after the HCG injection, by transvaginal ultrasound needle guided aspiration. This procedure is performed under anesthesia.
Synchronizing The Cycles of the Egg Provider and the Surrogate
As soon as ovarian stimulation is begun in the woman providing the eggs, the surrogate will start estrogen therapy (estradiol valerate). The estrogen is given twice weekly by injections. Ultimately, the surrogate will need to take progesterone as well to help prepare her uterine lining for implantation. GnRHa is administered for a period of 7 to 12 days in order to prepare the ovaries prior to administration of estradiol valerate. The duration of GnRHa therapy is adjusted to synchronize the cycle of the woman undergoing follicular stimulation with that of the surrogate.
Staggered-IVF with Surrogacy
Staggered IVF is well suited to gestational surrogacy. It permits candidates seeking this form of ART to defer, selecting the surrogate who will carry their baby until such time as they have “competent” vitrified blastocysts banked and ready for use. In addition the convenience factor, improved potential for success, reduced risk of miscarriage, multiple births and chromosomal defects, there is also a decided financial advantage with this approach. It eliminates the need to commit the sizeable and often non-refundable deposit that is often requested to secure the services of a gestational surrogate. With St-IVF, the surrogate doesn’t have to be chosen or committed until the candidates have viable embryos available.
Treatment: Building the Endometrial Lining of the Surrogate
The surrogate undergoes ultrasound examinations 10 days to two weeks after the first estradiol valerate injection to assess development of her uterine lining. Approximately four days prior to the expected day of embryo transfer, the recipient is given daily injections of progesterone to optimize endometrial development. In the uncommon event of poor endometrial development, the couple will be given the choice of either having the aspiring mother’s eggs harvested, fertilized, and frozen for transfer to a surrogate’s uterus in a subsequent cycle, or canceling the procedure.
Transferring Embryos to the Surrogate
Approximately 72 to 120 hours following egg retrieval (except in St-IVF cases), 2 (A predetermined number of embryos/blastocysts are transferred to the surrogate’s uterus. She then lies perfectly still for approximately one to two hours to enhance the chances of implantation and is then discharged from the clinic.
Following embryo transfer, the surrogate will be given daily progesterone injections and biweekly estradiol valerate injections and/or suppositories in order to sustain an optimal environment for embryo implantation. Approximately 10 days after embryo transfer, the surrogate will undergo a pregnancy test. In the case of a positive test (indicating that implantation has taken place), the hormone injections will be continued for an additional four to six weeks. An ultrasound examination will be performed at that time to confirm the pregnancy and the number of concepti that the surrogate is carrying.
If the test is negative, all hormonal treatment is discontinued, and menstruation will ensue within three to ten days. If the surrogate does not conceive, the aspiring mother may have her remaining embryos frozen, with the intention of having them thawed and transferred to the uterus of a surrogate at a later date. If, in spite of both the initial attempt and subsequent transfer of frozen/thawed embryos, the surrogate does not conceive, the infertile couple may schedule a new cycle of treatment.