Assisted reproductive procedures can be frustrating for the couple. Sometimes, even with healthy embryos, there are failures in embryo implantation. It is in these cases that endometrial scraping can be useful.
Endometrial scraping, also known as “scratching endometrial», is a minimally invasive intervention in which a lesion is induced in the inner layer of the uterus (endometrium) with the aim of promoting its regeneration to increase their receptivity during the embryo implantation process.
It is one of the procedures used in assisted reproduction for those women who do not achieve pregnancy due to repeated failures during implantation. Even so, it is not without its side effects and its benefits are still being discussed. Let’s see in detail what it consists of.
When is endometrial scraping indicated?
At present, endometrial scraping is indicated in women who have undergone at least two fertilization cycles in vitro and have suffered from repeated implantation failures. In other words, despite having good quality embryos, the embryo transfer process has failed.
It is possible that the problem has to do with the communication between the embryo and the uterus, since abnormalities in the eggs or sperm are not detected.
Endometrial scraping procedure
During endometrial scraping, a slight injury or ‘scraping’ is made to the mucous layer that lines the inside of the uterus, ie the endometrium. This is where the embryo is implanted. The intervention is safe, simple and does not last more than half an hour.
It is usually performed in a gynecological consultation by means of an endometrial biopsy, or through a hysteroscopy when one wants to visualize the uterine structure more thoroughly and rule out possible causes of embryo implantation failure.
In the process, a flexible catheter 3 millimeters thick is inserted through the cervix orifice to scrape the endometrium. This is similar to the one used for embryo implantation.
When performed by hysteroscopy, the inside of the uterus can be visualized. In this case, an endoscope is inserted that allows not only scraping the walls, but also using its camera to search for polyps, adhesions or anatomical malformations.
When should it be scheduled?
The recommendation is to perform endometrial scraping in the middle of the luteal phase of the cycle that precedes embryo transfer. That is, around day 21 of the menstrual cycle in a regular woman or one week before the probable date of menstruation of the cycle in which the embryo transfer is planned.
Embryo transfer can be of embryos fertilized with an egg and a sperm from the couple or by embryo donation.
What should be taken into account at the end of the procedure?
Once the intervention is finished, the recommendation is Avoid having sex the same night. In addition, the use of tampons or a menstrual cup should be avoided during post-procedure bleeding.
How does endometrial scraping work?
The mechanism by which endometrial scraping increases the chances of embryo implantation is still unclear. However, it is suggested that inducing a lesion in the endometrium causes an inflammatory response that favors tissue regeneration, which improves the connection between the endometrium and the embryo.
This reaction causes the release of growth factors, different chemical substances and some hormones that favor the repair of the epithelium. Added to this, it is believed that it can activate genes responsible for implantation.
Adverse effects of the intervention
Endometrial scraping, being a minimally invasive technique, is considered safe. In general, it has very few side effects. It is common for light bleeding to occur after the intervention, as well as abdominal cramps similar to those experienced during menstruation.
On the other hand, in very rare cases, pelvic infection or incidental uterine perforation may occur. The most important thing is to rule out pregnancy by searching for the gestational sac by transvaginal ultrasound, since endometrial scraping would cause a spontaneous abortion if pregnant.
Controversies about the intervention
In 2021, a review of multiple studies was published through Cochranein which the authors concluded that there is insufficient evidence to support the use of endometrial scraping as a method to increase the clinical pregnancy rate.
For previous, it is not recommended that it be routinely offered to women that will undergo the fertilization procedure in vitro.
There is insufficient evidence to support that there is a statistically significant difference in increases in clinical pregnancy and birth rates when used.
Over the years it has been suggested that it may increase embryo implantation. However, its effectiveness has been determined only in the rates of women with previous implantation failure.
In any case, as it is a minimally invasive, safe and economical procedure, an alternative is still being considered, especially in couples in developing countries, or after two or more fertilization attempts in vitro failed.
It is necessary that the study of the effects of its employment be continued to determine its true benefit.
What is there to remember?
Right now, assisted reproduction options are varied and can be adjusted to individual needs. Therefore, before opting for an endometrial scraping, It is convenient to investigate its benefits and disadvantages. The ideal is to resolve all doubts in the hands of a professional in gynecology.
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