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Surrogacy 101: Embryo Transfer

I’m Meriel, one of the Journey Coordinators at Collective Surrogacy, and I am a three-time past surrogate. In this Surrogacy 101 installment, I will be covering what to expect leading up to and after the embryo transfer. This is one of the most exciting parts of the journey but can also cause angst as everyone waits anxiously for results at each step.

Woman smiling from medical bed with blue cap
Awaiting my own FET in 2019

After all medical and legal clearances are given, the fertility clinic will develop an embryo transfer cycle calendar. This calendar will list when medications are taken and what dates the surrogate will be seen for bloodwork and ultrasounds to check progress as the body prepares for embryo transfer. 

The medications to be taken will vary depending on the reproductive endocrinologist setting the protocol. Most surrogates will first be placed on a birth control pill in order to better control the timing of the embryo transfer. These are then discontinued to induce a menstrual cycle, after which other medications will be started to prepare the uterine lining for transfer. The medications that may be used include (but are not limited to): orally administered Estrace, injectable estradiol, injectable progesterone in oil, progesterone administered via vaginal suppositories, aspirin, and, of course, a prenatal vitamin. It is very rare that a protocol doesn't include injectable medications, so this is aspect of the journey is one surrogates need to feel comfortable with.

For the lab work and ultrasounds, your Collective Surrogacy Journey Coordinator will find a clinic as close to the surrogate as possible that is able to complete the necessary tests. Labs include estradiol and progesterone level tests, and the transvaginal ultrasounds check the uterine lining. These appointments occur in the morning so the clinic receives results same day to adjust medications, if necessary.

The most important appointment occurs 1-2 weeks prior to the embryo transfer date - this is called the "passing ultrasound" appointment, and most clinics are looking to ensure your uterine lining has achieved at least an 8-millimeter thickness with a trilaminar (triple) pattern to know it is ready to receive the embryo.

The embryo transfer will include travel to the fertility clinic, with the surrogate arriving the day before and staying 1-2 nights after the transfer to rest as the embryo implants. Surrogates have the option to bring a companion with them for this trip. 

Woman smiling sitting up in a bed
On my bed rest orders post transfer

Many surrogates ask me if the transfer is painful. I have had a total of 7 transfers and would say that it is no more uncomfortable than a regular pap smear. Using a transvaginal ultrasound and camera, the doctor will insert a small catheter into the uterus and deposit the embryo near a “perfect” spot in the lining in hopes it implants successfully and develops into a pregnancy. 

Fun fact! At the date of embryo transfer, a surrogate is technically 2.5 weeks gestation according to traditional pregnancy growth calculations that use the date of the last menstrual period as day one of gestation.

Next is probably one of the hardest parts of the whole process - in the surrogacy world, it's called "The Long Wait." This is the 9-10 days after embryo transfer when the first pregnancy blood test happens. Some surrogates will do at-home testing starting around 5 days after transfer, and some choose to wait for the blood test. If the first blood test is positive, it will be repeated a couple of days later to be sure it is rising appropriately. A transvaginal heartbeat ultrasound is scheduled around 7-8 weeks of gestation (4-6 weeks after the embryo transfer). Once this is determined, the surrogate is typically released from the fertility clinic to her own OBGYN.

The chance of success on each transfer depends on a variety of factors, including the genetics used to create the embryo, embryo quality, whether the embryo has been genetically tested, etc. Success rates are typically very high but not 100%, of course. If a transfer is not successful, medications are discontinued and everyone waits for the surrogate's next menstrual cycle to plan the next transfer cycle.

Many parents and surrogates will try more than one attempt together, although everyone has the choice whether to continue with another attempt or not. As I have discussed before, I have experienced failed transfers and was eventually able to have three beautiful pregnancies and help complete two families. It is important to remember that a failed transfer is not a failed journey.

Here at Collective Surrogacy, we support our surrogates and intended parents through all of the ups and downs. Our Journey Coordinators will be there to answer any questions and help maneuver any bumps along the way. 

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