The Essential Guide to Understanding the ERA Test in IVF
During the IVF journey, you and your clinic have a shared goal: to help you start or grow your family. Thanks to the wonders of modern science, there are more ways than ever to improve the standard IVF process. Many clinics offer add-on treatments that enable patients like yourself to choose the pathway to pregnancy that feels best.
One of these treatments is the Endometrial Receptivity Array (ERA) test, which assesses the best time to transfer an embryo into the uterus, optimizing the timing so the embryo can successfully implant into the endometrial lining. You can choose this test for an additional treatment cost, but it’s essential to fully understand whether the ERA test will benefit your specific case before making the investment.
You’ll surely have a mile-long list of questions and thoughts when you hear about ERA tests. So, we’ve compiled all the need-to-know info in one place so you can feel confident that you’re making informed decisions along the way.
First things first: What is the endometrium?
The endometrium is the inner lining of your uterus, and it’s essential for embryo implantation. For a pregnancy to occur, the embryo must attach to this lining. So, before implantation, the endometrium undergoes hormonal changes to thicken and become more receptive, creating an ideal environment for the embryo.
During the IVF process, your clinic will monitor the endometrium’s development via ultrasound scans, particularly during the embryo’s blastocyst or morula stages. Your embryologists or doctor may prescribe you hormone medications to help ensure the lining becomes thick enough and receptive for implantation.
Once the endometrium has reached the optimal thickness and readiness, the clinic will proceed with the embryo transfer, either fresh or frozen, based on your treatment plan.
What is the ERA test, and how does it work?
The ERA test identifies the best time for the embryo transfer process (the “window of implantation”) based on when your endometrium is ready (which the doctors will call “endometrial receptivity”). The goal is to personalize the timing of the embryo transfer by identifying the window of implantation unique to your body.
Typically, doctors assess your endometrial lining with an ultrasound. However, during the ERA test, the clinic will take a sample of your endometrial tissue and analyze it to determine whether your endometrium is at optimal receptiveness. The ERA process takes about 4-6 weeks, including preparation and results waiting times.
The ERA test is an IVF treatment add-on that clinics may recommend to patients who:
- Have tried a few times to get a successful implantation.
- Have “thinner” endometrial linings.
- Have good-quality embryos but have still experienced a few unsuccessful embryo transfers.
- Are limited to how many future transfers they can try. For example, the embryos are being transferred by a surrogate, or only one embryo is available for transfer.
When does the ERA test take place during IVF?
The ERA test can happen during a natural or hormone-regulated cycle. It is usually carried out 7-9 days after ovulation (for natural cycles) or after the sixth day of progesterone medication (for hormone-regulated cycles).
You’ll undergo the same steps as a frozen embryo transfer (FET) to prepare your endometrium, such as taking estrogen and progesterone. However, the clinic will perform the ERA test instead of proceeding with the embryo transfer. You’ll receive the results 2-4 weeks after the biopsy, which will help the clinic determine your optimal window of implantation for the next cycle.
During that cycle, you’ll undergo a “personalized embryo transfer,” where your doctor transfers the embryo during the specific implantation window identified by the ERA test.
What happens during the ERA test?
Let’s review a step-by-step breakdown of what happens during the ERA test.
- The clinic will take a small biopsy of your endometrial tissue. The process is similar to a cervical smear.
- The tissue sample will be analyzed in the lab based on 248 genes to determine its “endometrial receptivity.”
- The results will identify whether the tissue is receptive, pre-receptive, or post-receptive.
Results
The results will show that your endometrium is either:
- Pre-receptive: This is before the window of implantation. In other words, the endometrium isn’t quite ready yet.
- Receptive: This is the ideal window of implantation unique to your body, meaning it’s the optimal opportunity to proceed with embryo transfer.
- Post-receptive: The window of implantation has passed, so the embryo transfer process may be less likely to be successful.
How to prepare for the ERA test and what to expect
Preparation is vital for every stage, procedure, and appointment during the IVF process, and it’s no different for the ERA test. Here are a few tips to help you feel confident and ready.
- Consult your fertility specialist: The clinic will advise whether an ERA test is right for you, what happens during the process, and the best timing.
- Schedule the test during the recommended cycle phase: The biopsy is usually scheduled 7-9 days after ovulation for natural cycles. It usually takes place on day 6 of taking progesterone for hormone-regulated cycles.
- Avoid certain medications: The clinic will advise what hormone medication to take. If you take other medications (like steroids or antibiotics), mention them to your doctor.
- Plan for mild discomfort: The ERA test can be uncomfortable and resemble menstrual cramps. Speak to your doctor if you’re concerned about any discomfort—you may be able to take pain relief before the biopsy.
- Arrange for time to rest: Follow your doctor’s instructions about rest. Usually, they’ll advise you to avoid strenuous activities and get plenty of sleep.
While the ERA test is considered a low-risk procedure, you might still experience a few symptoms like light bleeding or spotting. Although this is totally normal, it’s a good practice to let your doctor know when you see them. Biopsies have a minimal risk of infection, and your doctor will prescribe antibiotics if needed.
Is the ERA test effective? What the research says
Health organizations and governing bodies have yet to agree on the effectiveness of the ERA test and whether it positively impacts pregnancy or live birth rates. For example, the UK’s Human Fertilisation & Embryology Authority (HFEA) has given the ERA test a “red” rating, indicating that ERA tests “may reduce treatment effectiveness” based on “findings from moderate/high-quality evidence.”
In a recent study, the HFEA explained that any treatment add-on like ERA tests without “strong evidence” of safety and effectiveness should only be offered in research settings like clinical trials. A 2018 study also concluded that “performing the ERA test […] does not seem to improve the ongoing pregnancy rate.” On the other hand, a 2015 study found that an ERA test can contribute to higher pregnancy rates achieved via a personalized embryo transfer.
Ultimately, health organizations and researchers agree that more large-scale trials and research are needed to reach a definitive conclusion.
Alternative options for implantation success
There isn’t a clear consensus on how valuable the ERA test is, yet there are still many treatment decisions you and your clinic can make to optimize the chances of success. Embryo grading is a super important stage of your IVF journey, whether you decide to proceed with an ERA test or not.
Before the embryo transfer, embryologists grade all embryos to determine which ones are most viable for transfer. While traditional embryo grading methods like time-lapse imaging (TLI) are sometimes affected by human error and a lack of visibility, technology like AIVF is creating a new era of analysis.
AIVF leverages sophisticated AI and computer vision technology to identify patterns and anomalies in time-lapse embryo images that embryologists can’t see. Using our advanced AIVF Genetics platform, embryologists gain exceptional visibility into embryo health to make unbiased, data-driven decisions about the best embryos for transfer.
This high precision leaves less room for subjectivity and speeds up the embryo selection process, resulting in high success rates and a more positive experience for all IVF patients.
The positive impact of technology on every part of your IVF journey
ERA testing is continually developing as new technology comes along, and further large-scale trials will be on the horizon to improve the safety and experience of IVF patients.
AIVF gives you total visibility over the health of your embryos, providing you with a more reliable, accurate, and standardized embryo grading experience. Our embryo scoring is totally noninvasive, with no potential harm or risks to your health, giving you a much smoother and kinder IVF experience.
Want to feel confident that you’re choosing treatment options that improve your chances of a successful pregnancy? Find an AIVF clinic near you to take the first step today.