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The endometrial receptivity test is a test that determines the ideal moment to perform an embryo transfer, also known as the implantation window. This timing can differ depending on the patient. We know that 3 out of 10 patients have a displaced implantation window.
Endometrial Immunology and pregnancy
Calculating the endometrial implantation window
The endometrial receptivity test is a test that determines the ideal moment to perform an embryo transfer, also known as the implantation window. This timing can differ depending on the patient. We know that 3 out of 10 patients have a displaced implantation window.
What is the endometrial receptivity test used for?
The endometrium is the mucous membrane that covers the inner part of the uterus. It changes during the menstrual cycle and prepares itself for embryo implantation. It will only be “receptive” when the endometrium has the right thickness and the necessary conditions to allow a dialogue between the embryo and the endometrium.
The endometrium is only receptive for a short period of time, from 12 to 48 hours. But this is not always the case: it is crucial to know the details of each patient’s implantation window to increase the chances of embryo implantation.
How is it for?
The endometrial receptivity test is recommended in IVF, Egg Donation, Embryo donation and ROPA method treatments since the transfer should be performed at the moment of maximum receptivity. This test is particularly important in the following cases:
- History of implantation failure in previous treatments after transfer of good quality embryos.
- Unexplained infertility.
- Treatments in which a preimplantation genetic testing (PGT) is performed.
For each patient, Vida Fertility Institute specialists will do everything to determine the causes of infertility and find the most appropriate solutions for their case. Sometimes, the endometrial receptivity test is combined with the endometrial immunology test to complete the study and increase the chances of the embryo implantation.
What’s the Endometrial Receptivity procedure?
The endometrial receptivity test is a very simple test that consists of taking a small sample of endometrial tissue after completing an endometrial preparation cycle. The purpose of this test is to reproduce the exact conditions of an embryo transfer, to check if the endometrium meets the right conditions for future embryo implantation and to determine the exact moment to plan the embryo transfer.
Endometrial preparation is a simple treatment, involving the administration of estrogen and progesterone, orally, vaginally or by patch. At the time of what would be a “normal” implantation window, we will perform an endometrial biopsy. Depending on the results of the receptivity study of this sample, we will plan the precise time of the embryo transfer.
What happens after the Endometrial Receptivity Test?
After the biopsy, the sample obtained will be analysed using mass sequencing technology to determine whether the endometrium is receptive or whether it needs different prior preparation. In this way, for future embryo transfer, we will have to follow the recommendations based on the results obtained and we will personalise the strategy to be followed in each case.
FAQs about the endometrial receptivity test
For implantation to occur, the embryo must encounter an endometrium in its optimal phase: what we call a receptive state. This moment only occurs during specific days of the cycle.
At Vida Fertility, we can check whether your endometrium is receptive using an endometrial receptivity test (such as ERA), which analyses the genetic expression of the endometrial tissue and tells us the exact moment when your uterus is ready to receive the embryo.
Yes, in some women the implantation window may be shifted: that is, it does not occur when expected according to a standard cycle. This can happen for many reasons, such as hormonal variations, previous treatments, individual endometrial characteristics or immunological causes.
Detecting this shift is key to adjusting the timing of the embryo transfer and improving the chances of success.
The ERA (Endometrial Receptivity Analysis) test is performed by means of an endometrial biopsy scheduled during a simulated transfer cycle. The sample is sent to a specialised laboratory, where the genetic expression profile of the endometrium is analysed.
This analysis determines whether the endometrium is in a receptive phase at that time or whether the embryo transfer needs to be brought forward or delayed to coincide with the optimal implantation window.
The ERA test has an additional cost to the IVF treatment and its price may vary depending on the laboratory that processes it.
At Vida Fertility, we will provide you with a fixed, personalised quote, only if it is considered appropriate in your case (for example, if you have had unexplained implantation failures or several negative cycles with good quality embryos).
An endometrial biopsy is a simple procedure that involves taking a small sample of tissue from inside the uterus. It is performed without anaesthesia in the clinic and takes only a few minutes.
It is used to analyse different aspects of the endometrium, such as its receptivity, immunological profile or the presence of structural or molecular alterations, and is essential for personalising treatment and increasing implantation rates.
At Vida Fertility, you can have the entire process, from the endometrial biopsy to the interpretation of the results, at our fertility clinics in Madrid and assisted reproduction centre in Alicante.
We have a team that is highly specialised in endometrial medicine and embryo implantation, which will tell you when and how to have the test and will adjust your treatment according to the results.
For our international patients, we also offer the possibility of performing the procedure remotely, by sending a specialised kit, ensuring the same reliability and continuous medical support throughout the process.
The implantation window is the specific period of the menstrual cycle when the endometrium is receptive for the embryo to attach and initiate pregnancy. It usually occurs between days 19 and 21 of the cycle (in regular cycles), but in some women it may be displaced or altered, preventing implantation even with good quality embryos.
A displaced implantation window indicates that the optimal time to transfer the embryo does not coincide with what is considered the usual pattern. This can lead to repeated implantation failures, even when the embryos are genetically healthy. At Vida Fertility, we can diagnose this with an endometrial receptivity test and adjust the exact timing of the transfer to optimise the chances of success.
Specialists in endometrial receptivity testing
I am Beatriz Lozano, director of the fertility laboratory at Vida Fertility. With extensive experience in reproductive genetics, my goal is to help you identify the embryo with the greatest potential for success, reducing the risk of miscarriage and hereditary diseases.
‘A perfect embryo needs the perfect moment to implant. And that moment is different for every woman.’
We often encounter patients with good embryos who are unable to achieve pregnancy. In these cases, studying endometrial receptivity can be the key to understanding what is going wrong.
At our clinics in Madrid and Alicante, we perform the endometrial receptivity test with maximum precision and within the context of personalised treatment. Knowing your exact implantation window allows us to transfer the embryo at just the right time, thereby increasing your chances of success from the first attempt.
Patient experiences at Vida Fertility
It is incredible how, from absolute resignation, these doctors have lifted my spirits. They got me pregnant and gave me my life back. They live up to their name.
I had to find a way to become a mother if I wanted to pursue my career and not settle for just any partner. I made the right choice.
From the very first moment I felt I was being listened to, understood, and above all, I felt that my treatment was finally going in the right direction.
Hello dear Mrs Ortega,
you and the whole team of Vida fertility make us so happy. Finally a relief that we can be helped! Many thanks to you and all the others for the great care and exceptional quality work. This high quality means a lot to us. We hope that in 2024 we can take a healthy baby full of love into our arms.❤️
Thanks to Dr. Kathi’s support and by following all her advice, the best moment of the treatment came: I got pregnant.
I didn’t know if I would ever be able to get pregnant and now I’m in my 5th month of pregnancy.
It hasn’t been an easy journey. After the second attempt, I am happy to say that in two months I will be meeting my little girl.
Being able to experience this shared motherhood has been a gift for the two of us.
THANK YOU to this great team for everything!
We highly recommend Vida Fertility to anyone who has already given up hope and wants to give it one last try.
A huge thank you to the entire Vida Fertility team, especially to Sophie and Dr. Spies, who helped us achieve the wonderful project of expanding our family. We met a very competent team who perfectly guided and advised us on the medical choices to make at each stage of our journey. 🫶
I recommend Vida Fertility for their professionalism, humanism, and availability.
Our wonderful baby is the proof that the results are there!
Thank you!
Thanks to Vida fertility, we are now mums. Mums!!
It’s the greatest gift of all, we’re so happy!
The good feeling will certainly have contributed to the success of the treatment.
When we first contacted the clinic, I didn’t expect to become a mum so quickly, and now I even have hope that we might be able to create a sibling for our son with the remaining blastocysts.
Thank you!
I chose Vida Fertility because it’s a clinic that offers human support from the very beginning. I’m convinced that my state of mind, so influenced by the unconditional support they gave me, was key to the success of my treatment.
At the first consultation, I felt heard, understood, and full of hope again. The final transfer, our last chance, took place in February 2024… and it worked. Our little girl has brought immense joy to our whole family.
Being a single parent brings challenges, but I’d recommend anyone thinking about it to go for it. Vida Fertility made my dream come true with my first IVF.
