It is a state-of-the-art diagnostic method, which was developed and patented by
IGENOMIX after more than 10 years of research. This technique evaluates the status of the endometrial receptivity in the molecular point of view. The ERA is a personalized
genetic test to diagnose the state of endometrial receptivity in the window of implantation.
The endometrial receptivity is the status in which the endometrium is ready for embryo implantation to take place. This occurs around days 19-21 in each menstrual cycle of a fertile woman. Until now, the only study done on the endometrium was an ultrasound scan, and there was no any other analysis method available.
The ERA test allows us to diagnose whether the endometrium is receptive or not by analysing the expression of a group of genes related to endometrial receptivity. For that, an endometrial biopsy must be performed at P+5 (hormone replacement therapy cycle) or at LH+7 (natural cycle), and after its shipment to our installations, the expression of 238 genes is analyzed. RNA obtained from an endometrial tissue sample is hybridized in a custom microarray with probes for those genes. After hybridization, a computational
predictor classifies the sample as receptive or non receptive according to its specific
expression profile.
The result from the test will determine if a woman is receptive or not in the day and kind of cycle in which the biopsy has been performed. If she is receptive, it means that her window of implantation is placed in the day in which the biopsy was performed and
therefore the blastocyst could implant during this day and kind of cycle.
A non receptive result could imply a displaced window of implantation. Therefore, a
second biopsy would be needed in order to validate this displacement. A specific day for the second biopsy will be suggested according with the first result obtained. This will
allow the implantation in a subsequent cycle with a Personalized Embryo Transfer
(pET).
This test has been tested in patients who have had implantation failure with embryos of good morphological quality (at least 3 failed embryo transfers for younger women or two
in patients 37 years or more). This test is recommended for patients with apparently
normal uterus and with normal endometrial thickness (≤6mm), in which no problems are apparent.
1. Being a receptivity endometrial diagnostic method, the ERA determines the
personalised window of implantation for each patient before to begin an assisted
reproductive treatment.
2. The ERA test has shown high sensitivity and specificity detecting gene
expression profiles associated with receptivity.
The inner lining of the uterus is called the endometrium. Every month it is prepared for the
arrival of an embryo and it is in this place the embryo implants to grow in to a baby. When this
does not occur, menstruation begins shedding the endometrial lining. Defect in the endometrial
lining is one of the reasons for failure in implantation and infertility.
Endometrium is receptive when it is ready for embryo implantation to occur, which usually takes place between 19-21 days of the menstrual cycle(5-7 days post ovulation). This period is called
Window of Implantation.
This is a molecular diagnostic tool to study 238 genes related to endometrial receptivity taking a
specimen from the endometrium.
It is used to evaluate the stage of an endometrium and to determine whether it is receptive or non
receptive.
In the case of non-receptive endometrium, the test allows us to find a correct window of
implantation for each person.
ERA identifies the probable day (window of implantation) when the embryo is capable of
implanting in the uterus.
1) For couples with recurrent implantation failures with good quality embryos.
2) At least 3 implantation failures in young women.
3) Two in patients 35 years or more.
A defective window of implantation is detected in approximately 25% of these women.
Repeated IVF failures due to poor ER
Poor ER (< 0.6 mm)
Post menopausal women
Premature ovarian failure
Small Uterus grown with hormone
Before starting ART treatment, the ERA can identify if the patient will require a change in date
compared to the usual day transfer. If there is a change it helps us to take appropriate action to
change the date of embryo transfer to be more successfull especially if embryo quality is good.
The blastocyst transfer should be performed in the same type of cycle and the same day on which
a receptive report was obtained. A receptive endometrium implies that this is the day on which
the blastocyst transfer should be performed. If the day 3 embryo is going to be transferred then
the transfer should be 2 days earlier.
