By Dr. Sara Fueyo Pestaña (Gynaecologist – Reg. No. 202008718).
Immunological infertility occurs when the body’s immune system negatively interferes with the reproductive process, attacking sperm or preventing the proper development of the embryo.
In some cases, a woman’s immune system may mistake sperm for foreign agents, triggering a reaction that destroys them. Similarly, the body may attack the embryo in its early stages, leading to implantation difficulties or even recurrent pregnancy loss.
It is estimated that 2 out of 10 couples experience some type of fertility issue, and a portion of these difficulties may be related to immunological causes, although exact statistics on its prevalence are not available.
Immunological infertility can lead to implantation failure due to an abnormal immune response. In some cases, the woman’s immune system does not properly recognize the embryo’s signals, which may interfere with embryonic DNA and halt its development.
Another manifestation of immunological infertility is the repeated rejection of the embryo, perceived by the body as a foreign agent. This occurs due to the formation of antibodies that attack the embryo or the placenta, increasing the risk of miscarriage.

Diagnosing immunological infertility requires several tests, including blood tests to detect antibodies and markers of inflammation or autoimmune diseases. It is also common to perform a thrombophilia study to identify factors such as lupus anticoagulant, anticardiolipin antibodies, and others that may cause abnormal blood clots, which can affect embryo implantation.
Another key aspect is measuring the activity and quantity of natural killer (NK) cells. If these cells are abnormally active, they can interfere with both implantation and embryo development.
At IVF-Life, as part of our extended studies for implantation failure or recurrent miscarriage cases, we offer an advanced diagnostic tool called the immunological study. This test involves an endometrial biopsy during the luteal phase (the phase of the menstrual cycle when ovulation occurs) and a blood test to monitor immunotherapy.
With this test, we can accurately assess the distribution of immune cell populations, especially the number and activity of endometrial NK cells, as well as the balance of T lymphocyte subpopulations. This allows us to identify alterations in immune profiles that may be affecting implantation and embryo development.
Thanks to these results, our medical team can design a personalized treatment plan to restore immune balance and improve the chances of a successful pregnancy.

Treatment usually involves the use of immunomodulators, such as corticosteroids, to reduce the immune response and support embryo implantation.
Anticoagulants and antiplatelet agents are also used to prevent the formation of blood clots that could interfere with implantation. Additionally, specific treatments are available to modulate the immune response, thereby improving the chances of success.
The most important step is to correctly identify the cause of infertility, which allows for a personalized treatment plan tailored to each couple’s needs. It’s important to remember that immunological infertility is a complex condition, but there are various tests and treatments available to address it.
If you’ve experienced difficulty conceiving or have suffered recurrent miscarriages, it’s essential to consult a specialist to determine whether an immune-related cause may be affecting your fertility. At our clinic, our specialized medical team can help you better understand your situation and offer the most appropriate treatment. Don’t hesitate to contact us to schedule a consultation or ask any questions you may have.