Endometrial preparation - The Embryon Family Fertility Center

The purpose of the medication used during a donor-assisted IVF cycle or embryo transfer is to optimally prepare your uterine lining for the embryo transfer at your preferred timing. Typically, this process takes between 10 to 21 days, with an average of around 14 days, to achieve the ideal thickness of the endometrium.

To prepare the recipients for embryo transfer, the following types of medications are utilized:

Estrogen and Progesterone (either natural or synthetic).

The initial phase of your hormonal treatment generally involves a cycle of estradiol and progesterone before the embryo transfer cycle. This step is designed to mimic the natural stages of a menstrual cycle, so whether you experience your own menstruation is not a concern.

Estrogen and progesterone play a crucial role in synchronizing menstruation with the selected timing for embryo transfer. They also support your uterus’s natural ability to build and shed the endometrial lining.

Natural estrogen tablets include Progynova, Progynon, Estradiol, Estrofem, and Femanest. For synthetic combinations of estrogen and progesterone, examples include Neovletta, Femoden, and Marvelon.

Down-Regulation

We are now at Step 2. You will receive one injection of a hormone that helps prevent early ovulation. This is important because early ovulation can change your “implantation window”; and lower the chances of successful implantation. This injection temporarily stops your ovaries from working for one cycle. It also helps prevent early ovulation and progesterone production, which could shift your implantation window and reduce success rates. Medications like Procren Depot (3.75mg – one injection), Diphereline Depot, Buserelin Depot, Zoladex, Decapeptyl Depot, or other GnRH agonists are examples of this type of treatment.

Some patients request to skip the down-regulation injection, often due to negative experiences with it during their previous IVF treatments. They mention that it affected their mood, concentration, and overall well-being, sometimes requiring them to take time off work and disrupt their daily lives for about a month.

However, the experience of “artificial menopause” during an egg or embryo donation cycle is generally milder than during long protocols of IVF with their own eggs. Before starting this phase, patients take estrogen and progesterone to help balance the effects of the injection. Additionally, the duration of artificial menopause in egg or embryo donation is much shorter, lasting no more than seven days, compared to up to three weeks in own-egg IVF, making it less likely for unwanted symptoms to occur. It’s important to know that not allowing down-regulation can change the timing of implantation and increase progesterone levels. This may lower the chances of successful implantation, making it unwise to transfer embryos on the planned date.

Considering these factors, many patients accept the idea of a brief artificial menopause, which helps them stay calm and proceed smoothly with their treatment plan.

Estrogen administration

Step 3 begins when you stop taking estradiol and progesterone from your previous cycle, leading to the start of your period. We will then ask you to schedule your first ultrasound with your local doctor to check the thickness of your endometrium and ensure no cysts are present.

Your preparation continues with estrogen tablets, cream, or patches to help thicken your lining for an embryo transfer. You will have a second ultrasound to monitor the growth of your lining and determine if you need more estrogen.

Both oral and transdermal forms stabilize hormone levels during and after the donation cycle. Estrogens help grow the endometrial lining in the uterus, preparing it for embryo transfer.

Estrogens help maintain the endometrium lining after embryo transfer, preventing menstruation until the embryonic placenta can take over hormonal support for your pregnancy. Standard estrogen tablets include Progynova, Progynon, and Estrodiol, while patches include Climara, Estradot, Evorel, and Vivelle. Patients often ask about the estrogen dosage needed before and two months after the embryo transfer, wondering if it might be too high. However, the prescribed doses are still much lower than the estrogen produced by the placenta during the second and third trimesters, meaning this external estrogen does not match the hormonal levels typical in a pregnant’s body.

Progesterone

Moving on to Step 4, you will start progesterone six days before your embryo transfer. You will need to use two forms of progesterone simultaneously: vaginal pessaries or cream and injections. Research shows that this combination effectively reduces the risk of early miscarriage in pregnancies resulting from egg donation or embryo adoption. Progesterone prepares the uterine lining for the embryo and helps maintain the endometrium after transfer, ensuring menstruation does not start before the embryonic placenta can provide hormonal support. Examples of progesterone medications include Crinone vaginal gel and Utrogest vaginal pessaries.

Additionally, vitamins and other medications may be prescribed to enhance blood flow in the uterus before, during, and after the embryo transfer. Some medications may also help lower the mother’s immune response to the embryo. After reviewing your medical history, we will tailor the necessary medications to your egg or embryo donation treatment plan.

Hormone medications and favored brands can vary between countries and among fertility specialists.

It is important to note that not every OBGYN or fertility specialist possesses the necessary experience in preparing a recipient’s endometrium for a donor-assisted embryo transfer. While this may seem surprising, it is indeed the case. Each year, we assist hundreds of women with IVF and egg donation, and we observe the outcomes closely. We collaborate with numerous international doctors and clinics that prepare their patients for embryo transfer, and we have observed varying success rates among different practitioners, with some patients experiencing repeated successful implantations while others face ongoing challenges.

It is important to recognize that not all instances of failed implantation can be attributed solely to the preparation of the endometrium or its thickness. Other factors may also play a role, such as the medication support provided after an embryo transfer and the potential for the endometrium to reject the embryo.

Should you require further information on this topic, please do not hesitate to contact us.

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