Introduction. The negative impact of chronic tonsillitis on the reproductive system of women has been established. Prolonged persistence of infectious agents leads to disruption of blood supply to the endometrium and prevents normal implantation of the trophoblast. Some unexplained reproductive losses may be caused by immune causes, including those associated with chronic tonsillitis.Aim. To study the prevalence of various forms of chronic tonsillitis and the state of humoral immunity in women with habitual miscarriage, to evaluate pregnancy outcomes after treatment of chronic tonsillitis in this group of patients.Materials and methods. The main group consisted of 45 patients with a history of miscarriages and chronic tonsillitis who were treated for chronic tonsillitis before planning pregnancy. The control group consisted of 41 patients with spontaneous miscarriages and chronic tonsillitis who were not treated for chronic tonsillitis before planning pregnancy. The treatment included flushing of the tonsillar lacunae and physiotherapy. The immunological study included a spectrum of antiphospholipid antibodies by solid-phase enzyme immunoassay (ELISA).Results. In the study of humoral immunity in the main group, elevated levels of aß2-GP-I were noted in 25 (55.6%), anti–HCG in 22 (48.9%), aCL in 17 (37.7%), aPT in 12 (26.7%), and aAnV in 10 (22.2%), aFS – in 8 (17.8%) patients. All patients in the main group underwent a course of treatment for chronic tonsillitis before planning pregnancy. A month after treatment, a decrease in the level of antiphospholipid antibodies was noted. Spontaneous termination of pregnancy in the early stages occurred in 2 (4.4%) women of the main group and in 8 (19.5%) patients of the comparison group (p = 0.043).Conclusions. Clinical studies have proven the relationship of bacterial and viral infections with early miscarriages and premature birth. Infections accompanied by increased production of pro-inflammatory cytokines play an important role in miscarriage. Reducing autoimmune activity and reducing autoantibody levels after CT treatment helps reduce the incidence of pregnancy complications.