With IVF, one of the most important steps is the frozen embryo transfer.
It’s where your fertilized egg and sperm have spent around 3-5 days in the lab, and grown into a ball of cells called the embryo.
But the lab can only do so much. It’s now time for the embryo to shift into its natural habitat, the uterus.
At times, the uterus is also checked for whether it’s prepared the right environment to welcome and house this embryo for the next nine months.
Wondering where we’re going with this? This is exactly where Endometrial Receptivity Assay (ERA) comes in.
Let’s learn all about it.
Table of contents
- What is ERA?
- What is the Window of Implantation?
- How can ERA testing in IVF help?
- Who is the ERA fertility test recommended for?
- How is the ERA done?
- Is ERA a biopsy?
- How to prepare for ERA?
- ERA and how it helps with IVF
What is ERA?
The Endometrial Receptivity Assay (ERA) is a genetic test designed to assess the receptivity of the uterine lining (endometrium) to embryo implantation.
But wait, how do we do that? This test analyzes the expression of 248 genes involved in endometrial receptivity, providing a molecular snapshot of the uterus’s readiness to accept an embryo.
ERA goes beyond traditional methods of assessing endometrial receptivity, such as ultrasound or blood tests.
While we dig into the genetics part with ERA, it helps by offering a more precise and personalized evaluation of when the uterus is most likely to be receptive to an embryo.
What is the Window of Implantation?
Along with ERA, we need to focus on the window of implantation as well. The window of implantation (WOI) is a natural phase which refers to the brief period when the endometrium is optimally prepared for embryo attachment.
Typically, this window occurs around days 19-21 of a woman’s menstrual cycle and remains open for about 24-48 hours.
However, the timing of this window can vary from woman to woman, and especially with treatment such as IVF. Some may have an earlier or later window of implantation, which can impact the success of embryo transfer in IVF.
And with frozen embryo transfer, you may be medicated as well prior to the cycle, to help your uterine lining grow to the desired thickness. Understanding and identifying this personalized window is key for implantation in natural or assisted reproductive cycles.
How can ERA testing in IVF help?
ERA testing in IVF offers several benefits:
1. Personalized timing: ERA helps identify the optimal time for embryo transfer based on each woman’s unique genetic profile.
2. Improved implantation rates: By ensuring embryo transfer occurs during the window of implantation, ERA can potentially increase the chances of successful pregnancy.
3. Reduced risk of repeated implantation failure: For women who have experienced multiple unsuccessful IVF cycles or repeated implantation failure, ERA can help identify if the timing of embryo transfer might be a factor.
4. Emotional and financial benefits: By potentially reducing the number of IVF cycles needed, ERA can help alleviate some of the emotional stress and financial burden associated with fertility treatment.
Who is the ERA Fertility Test Recommended For?
While the ERA test can be a valuable tool in the IVF process, it’s not necessary for all patients. Your fertility specialist may recommend ERA in the following situations:
- Recurrent Implantation Failure: If you’ve undergone multiple IVF cycles with good-quality embryos but haven’t achieved a successful pregnancy, ERA may help identify if the timing of embryo transfer is a factor.
- Advanced Maternal Age: Women over 37 may benefit from ERA, as the implantation window can become more variable with age.
- Unexplained Infertility: For couples with unexplained infertility, ERA might provide additional insights into potential implantation issues.
- Previous Pregnancy Loss: If you’ve experienced biochemical pregnancies or early miscarriages, ERA can help determine if implantation timing might be a contributing factor.
- Optimizing IVF Cycles: For patients looking to maximize their chances of success in fewer IVF cycles, ERA offers a personalized approach to embryo transfer timing.
How is the ERA fertility test done? A Step-by-Step Process
The ERA test involves several steps:
1. Endometrial biopsy: A small sample of the endometrium is collected, usually during a mock embryo transfer cycle. A mock embryo transfer cycle is done by inserting a flexible catheter inside, and to note down the cervix position and required details for the actual transfer.
2. Gene expression analysis: The biopsy sample is analyzed to assess the expression of genes associated with endometrial receptivity.
3. Data interpretation: The results are interpreted to determine the personalized window of implantation.
4. Treatment planning: Based on the results, the fertility specialist can plan the optimal time for embryo transfer in subsequent IVF cycles.
Is ERA a biopsy?
Yes, ERA does involve a biopsy of the endometrium. However, it’s important to note that this is a minimally invasive procedure:
- The procedure is quick, usually taking only a few minutes.
- While some women may experience mild discomfort, similar to a Pap smear, the procedure is generally well-tolerated.
- No anaesthesia is required. However, based on your comfort, you may request for the same.
How to Prepare for ERA?
Here’s your mini checklist on how to prepare for an ERA procedure:
1. Consultation: Discuss the procedure with your fertility specialist to understand if it’s right for you.
2. Cycle monitoring: You may need to track your menstrual cycle or undergo a mock embryo transfer cycle.
3. Medication: Some women may be prescribed hormonal medications to prepare the endometrium.
4. Timing: The biopsy is typically scheduled 5-7 days after the LH surge in a natural cycle, or 5-7 days after progesterone administration in a hormone-replacement cycle.
5. Day of procedure: No special preparation is needed on the day of the biopsy. You can eat and drink normally.
ERA and how it helps with IVF
IVF treatments are getting better on the daily, with procedures such as Endometrial Receptivity Assay getting a makeover in the years to come as well.
With advanced technology and the introduction of AI, maybe we’ll move on to non-invasive ways of checking the receptivity over a traditional biopsy.
While ERA isn’t necessary for all IVF patients, it can be particularly beneficial for those who have experienced repeated implantation failure. As always, it’s best to discuss the potential benefits and considerations of ERA with your fertility specialist.
Remember, every fertility journey is unique, and ERA is just one of many tools that can help improve your fertility journey.
