By Mamie McLean, MD

We met a very special baby in the office this week. A very long-awaited son born to a couple who’d been trying to conceive for over five years. This couple had run into almost every obstacle possible in the reproductive world, even running into rare complications that most patients never have to experience.

They met all of this with grace, hope, and persistence. They saw every clinic in town, searching for answers that would give them the child they had waited so long for.

The Link Between Recurrent Implantation Failure and Endometrial Receptivity

After the couple had experienced two unsuccessful embryo transfers, despite normal genetic testing of the embryo, our team realized that endometrial (inside of the uterus) receptivity could be the problem.

During the frozen embryo transfers, we utilize two medications to prepare the endometrium (inside of the uterus) for the transfer, including estrogen (pills, shots, or patches) and progesterone (usually injections). This is because the endometrium requires a very specific amount of progesterone prior to the embryo transfer to ensure optimal conditions for implantation (embryo sticking).

In natural conceptions (aka without our fancy treatments), the body knows just what to do and is perfectly designed. Once the egg is released from the ovary during ovulation, the area left behind on the ovary (the follicle) is a hormone machine, making the estrogen and progesterone necessary for the embryo to implant about 5-6 days later. This is the amount of time that it takes the embryo to travel down the fallopian tube and reach the inside of the uterine cavity for implantation.

In assisted reproduction cycles, we’re trying to recreate this sophisticated exposure of hormones on the endometrium. We find that some patients (around 30%) need slightly more or slightly less progesterone for the embryo to implant.

Finally, a Breakthrough: Endometrial Receptivity Analysis (ERA)

In the past, we haven’t had much to offer patients who’ve had multiple failed embryo transfers in the way of diagnosis and treatment. But this is changing—primarily with genetic testing on embryos becoming more and more common. Recurrent implantation failure, or lack of pregnancy after two embryo transfers, boils down to two main areas: the embryo and the uterus.

For this specific couple, we knew the embryos being transferred had normal DNA and, thus, were not the cause of the lack of implantation so we performed a test called an Endometrial Receptivity Assay or Analysis (ERA).

For the ERA, the patient goes through a “mock cycle,” simulating the medications and timeline of an actual frozen embryo transfer. But instead of the transfer, we perform an endometrial biopsy where we take a small amount of tissue from the inside of the uterus (a process that’s similar to a pap smear) and send it off for testing.

The testing company analyzes the tissue and can tell us if the patient needs more or less progesterone than that which was given during the mock cycle. That’s when we get geared up again for a frozen embryo transfer, adjusting the progesterone start date accordingly. The shifted progesterone window helped this couple conceive and have their son.

Kind of amazing, isn’t it?

Is the Endometrial Receptivity Analysis the answer you’ve been searching for?

The negatives of the ERA are time—it can add a month of treatment to what is already a long process–and cost, as it can run add hundreds of dollars to an already expensive treatment process.

The science of our field changes rapidly and is allowing us to help more and more patients. Nowhere are these advances more tangible, than for patients with recurrent implantation failure.

Learn more about the Endometrial Receptivity Analysis, implantation failure, and other fertility testing methods from Alabama Fertility in Birmingham, AL

At Alabama Fertility Specialists, we treat all patients with the care and compassion that complex reproductive issues require. We encourage you to ask your doctors and nurses at Alabama Fertility Specialists as many questions as you need to in order to find out more.