There are many causes of infertility in women, and one of them is a negative antibody test. Today, let’s learn more about closed antibodies. What are closed antibodies? In normal pregnancy, a specific IgG antibody produced by the maternal immune system can be stimulated by the paternal HLA antigen (trophoblast surface) carried by the embryo due to the incompatibility of the couple’s HLA antigens. In normal pregnant women, closed antibodies (+) can be detected in the early stages of immunity, while patients with recurrent miscarriage often have closed antibodies (-), making the maternal immune system susceptible to immune attack on the fetus and leading to miscarriage. Therefore, many scholars and studies have used the determination of confinement antibodies as one of the indications for immunotherapy of recurrent miscarriage and for efficacy determination, but controversy still exists. The functions of confinement antibodies are: 1. to protect and stimulate placental growth and differentiation; 2. to bind to maternal lymphocyte surface antigens on the one hand, and to the trophoblast itself, thus blocking immune recognition and response between mother and fetus and making mother-fetus tolerant. In summary, if the maternal serum is deficient in closed antibodies, it may lead to spontaneous abortion. Treatment: For patients with recurrent miscarriage with closed antibodies (-), immunotherapy with the husband’s lymphocytes can be used to induce the mother to produce the corresponding closed antibodies. How to do this: Husband draws venous blood – isolates husband’s lymphocytes – wife receives subcutaneous multi-point injection of husband’s lymphocytes. A total of 3-4 immunotherapy sessions are performed before conception, every 3-4 weeks. After the third immunotherapy session, the antibody is retested, and if the antibody turns positive, the pregnancy is successfully carried out within 3 months of the turn, if possible, and every 3-4 weeks around 6 weeks of pregnancy, for a total of 3-4 sessions. Happily, clinical data show that immunotherapy is effective in a proportion of patients with recurrent miscarriages with closed antibodies (-). Patients with recurrent miscarriages of unknown origin have a treatment efficiency of >95% and a pregnancy success rate of >95%, while 10-20% still miscarry.