In recent years, under the combined influence of factors such as life stress, unhealthy habits, environment, and advanced maternal age, the occurrence rate of recurrent pregnancy loss (such as recurrent miscarriage, fetal demise, recurrent biochemical pregnancy, etc.) has gradually increased.
Among patients with recurrent pregnancy loss, the presence of blocking antibodies is often lacking, meaning their tests for blocking antibodies are often negative.
Why does a negative result for blocking antibodies lead to recurrent pregnancy loss? How should negative results for blocking antibodies be treated? Find out with Director Zhu Xiuying, who has nearly 40 years of experience in the frontline of infertility clinics.
01. What are blocking antibodies? Why should they be positive?
The so-called “blocking antibodies” are protective antibodies produced by the mother after being exposed to paternal antigens during normal pregnancy.
We all know that an embryo is formed from the combination of the maternal egg and paternal sperm, with genetic material half from the mother and half from the father. However, as the carrier of the embryo, the mother may reject the “paternal genetic material” during implantation and development, leading to an immune response against the embryo. If the blocking antibodies are positive, this attack will be blocked, allowing the embryo to successfully implant and develop into a full-term fetus. Conversely, in the case of negative blocking antibodies, there is a higher risk of miscarriage, or even recurrent miscarriages.
02. Who should undergo blocking antibody tests?
Individuals with a history of adverse pregnancy outcomes, such as miscarriages, fetal demise, incomplete miscarriage, especially patients with recurrent miscarriages, should undergo routine blocking antibody testing.
For couples with negative blocking antibodies, specialized medical guidance and medication intervention are required during subsequent pregnancies.
03. How is the blocking antibody test performed?
It involves blood tests for both partners to check for antigens, so both the male and female need to schedule the test together. However, there is only one report for the blocking antibody test as the lymphocyte reaction requires blood samples from both partners to be mixed together.
Important notes for the test:
â‘ Avoid testing during menstruation;
â‘¡ You can have breakfast on the day of the test, but avoid excessively oily food;
â‘¢ Both partners should have their blood drawn simultaneously;
04. Is negative blocking antibodies an issue for the female or the male?
The absence of blocking antibodies results from an imbalance in immune tolerance between the embryo and the mother due to mutual immune recognition factors of both partners. Therefore, it cannot simply be attributed to either the female or the male; it is a mutual issue.
05. If the test results are negative, should treatment be administered? How is it done?
It is unlikely for a negative blocking antibody result to naturally turn positive after a period of waiting.
As for treatment, the goal is to induce the production of blocking antibodies in the mother, so treatment should be focused on the female. During pregnancy, immunotherapy is administered. Alongside medication, lifestyle changes are essential, such as quitting smoking, avoiding alcohol, late nights, maintaining a balanced diet, engaging in physical exercise to boost immunity and reduce the risk of miscarriage.
An important note is that the treatment method involving repeated inoculation of maternal forearms with lymphocytes from paternal origin or healthy males to stimulate the production of blocking antibodies in the mother has been largely abandoned.
