Gestational Surrogacy Process

It is necessary to synchronize the menstrual cycles of the surrogate and the intended parent in order to obtain mature eggs and embryos and transfer these back into a perfectly prepared endometrium (uterine lining) to maximize the chances of pregnancy success. This is done using a variety of hormonal manipulations including birth control pills, leuprolide (Lupron), or Synarel. We will determine which technique will work best for each circumstance. Once both women’s (surrogate and intended parent) ovarian function is suppressed and their cycles synchronized, they can begin the process of preparing for pregnancy.

On about the same day, the surrogate and intended parent will begin hormonal therapies to prepare the appropriate target for pregnancy success. The surrogate will begin taking estrogen to stimulate endometrial (uterine lining) growth and the intended parent will begin taking FSH to stimulate egg production. These treatments are monitored with ultrasound and blood estrogen levels until the eggs are ready to be retrieved and the uterus is ready to accept an embryo. Usually these treatments will take approximately two to three weeks and require five office visits for ultrasounds and blood tests.

When the ultrasound monitoring of the ovaries and uterus determines that the eggs are mature and ready to be retrieved and the endometrial lining is appropriately grown, the intended parent is scheduled for egg retrieval. On the day of the egg retrieval the intended parent undergoes a vaginal, ultrasound-guided procedure under light anesthetic at SDFC. The ultrasound used for egg retrieval is just like the one used to monitor the process of the cycle in the office. When the follicle that contains the eggs is seen with the ultrasound, a needle can be directed through the top of the vagina into the follicle and the follicular fluid and eggs are aspirated into a test tube. An embryologist works with the physician in the operating room to examine the fluid under a microscope and find the eggs. On the same day as the egg retrieval, the husband provides a fresh sperm sample and the surrogate begins progesterone treatment. Once the eggs are retrieved, they are taken to the IVF laboratory and placed with sperm in the incubator. The following morning it is determined how many of the eggs have successfully fertilized into embryos.

The embryos are allowed to grow in the lab for several days to make sure they are healthy and dividing properly. Nature tells us that not all human embryos are perfect and by allowing them to grow in the laboratory incubator, we can see which embryos are healthiest and most likely to result in a successful pregnancy. We usually allow the embryos to grow in the laboratory for somewhere between three and five days and then select a few of the best embryos for transfer into the surrogate uterus. The number of embryos placed in the uterus can greatly influence the success of the cycle, but also can increase the chance of multiple births. The determination of how many embryos to transfer is made carefully and only after we have all the information available about embryo quality, quantity, etc. This means waiting until the day of the transfer to make our final decision about the number of embryos to place into the uterus. Typically, we will recommend transferring two to three embryos into the uterus.

The actual embryo transfer procedure is a gentle, painless process. A soft tube (outer catheter) is inserted by the physician to a pre-determined position in the uterus. A smaller tube (inner catheter) is then loaded with the embryos and guided into the uterus through the outer catheter. The embryos are then injected into the uterine cavity and the catheter set removed. The embryologist inspects the catheters for retained embryos once the procedure is completed. The surrogate is then instructed to remain at home in bed for the next three days and continue her estrogen and progesterone treatments. A pregnancy test about two weeks (16 days) after egg retrieval will determine if the cycle is successful.

In successful cycles, the hormonal supplements are continued through the first trimester (12 weeks) of the pregnancy. Once the first trimester is completed and the placenta has matured to the point where it can provide for all the hormonal needs of the pregnancy, no further supplements are required. We will monitor blood levels of estrogen and progesterone at the end of the first trimester and taper off the hormone supplements gradually. Once the hormone supplements are stopped, the rest of the pregnancy is indistinguishable from any other pregnancy!