Finding the Cause of Infertility: Endometrial Testing


4 min read

If you have experienced multiple pregnancy losses or have had unsuccessful fertility treatment cycles, you may be a good candidate for further testing to determine if the cause is related to the environment within your uterus or uterine lining. Your doctor may suggest one or a few tests that use a small biopsy of your endometrial lining to analyze what’s going on inside your body. We put together a few details about some of the common tests and what they’re used for.

Getting Started

Before getting started with the endometrial testing, you first have to grow an endometrial lining. If you’re doing this testing prior to a medicated embryo transfer cycle, your doctor will likely want to use the same medication protocol that you would use for a transfer to grow the lining for testing. This means that you would take the same type of estrogen and progesterone medication (oral, vaginal, or injectable) that your doctor will prescribe for you to take in the cycle where you will transfer the embryo. That way, the medications and timing can be mimicked exactly or adjusted precisely based on the test results. The date of the testing will be timed around your natural menstrual cycle or alongside the start of progesterone depending on the cycle type your clinic has chosen for you. 

The biopsy is done in your doctor’s office and your clinic will provide you with the specific instructions to prepare for the test. 

The process of retrieving an endometrial sample tends not to cause much pain, but if it is uncomfortable for you, the pain is short lived because the process is very quick. If you are considering taking medication to help with discomfort either before or after the procedure, be sure to review with your doctor what your pain relief options are.

Collecting the Biopsy

Your doctor will insert a speculum into the vagina to visualize your cervix and will thread a small straw-like instrument through the cervix to scrape off a tiny portion of the endometrial lining. The instrument is removed from the uterus and the tissue sample is placed in a sterile liquid-filled cup and sent out for testing. 

A type of speculum.

Three Testing Options

There are three main test options that may be recommended for you based on your medical and pregnancy history. You may do one or all three of these tests. Let’s break them down and see what each test is for and what the results mean.

ERA (Endometrial receptivity analysis)

  • ERA is a test that helps determine the best time to transfer an embryo back into the uterus. There is a window of time that is optimal for an embryo to implant known as the window of receptivity. Most women have a similar window of time that is best for transfer, but according to Igenomix 30% of women have a window of time outside of the norm.

  • ERA looks for the expression of certain genes that indicate that the endometrial tissue is receptive to implantation of an embryo.

  • The ERA results will indicate if the sample is pre-receptive, receptive, or post-receptive at the time of biopsy.

If the ERA suggests that the endometrium is pre- or post-receptive at the time of biopsy, it will also make recommendations for adjusting the start of progesterone to optimize receptivity at the time of embryo transfer. 

ALICE (Analysis of Infectious Chronic Endometritis)

  • ALICE is a test that assesses the endometrial lining for signs of chronic endometritis. Endometritis is a bacterial infection in the lining of the uterus that causes inflammation and can interfere with implantation of an embryo

  • Oftentimes, chronic endometritis has no symptoms, which makes it hard to identify without ALICE. 

  • The results of the testing will be able to recommend antibiotics for treatment if chronic endometritis is detected. 

EMMA (Endometrial Microbiome Metagenomic Analysis)

  • The EMMA test analyzes the “good bacteria” contained in your endometrial environment. EMMA includes ALICE, meaning that it also checks for the presence of inflammatory bacteria that can cause chronic endometritis 

  • Depending on what is found on the the analysis, the test results may? recommend probiotics to boost microbiome or antibiotics to treat endometritis.

 Cost of Testing

Depending on your medical history, your doctor may suggest one or all three of these tests to help determine the reason for previous implantation problems or recurrent pregnancy losses. These tests are not typically covered by insurance, but it is worth checking with your specific plan to determine if any or all of the testing may be covered.

According to Invitra, you can expect to pay about $800 for the ERA, $300 for the ALICE, and $500 for the EMMA. Your clinic or the company performing the testing may provide a cheaper, bundle price if all 3 tests are ordered together.

The uterine environment is a crucial part of the success of fertility treatment and ultimately the success of implantation and pregnancy. Testing the endometrial tissue can shed some light on causes of infertility that were previously unknown. Talk with your doctor about whether these tests may be right for you.