A total of 70 females with threatened abortions induced by hormonal, infectious or unclear factors and 63 second trimester underwent clinical, hormonal and immunological investigations. In all females with threatened abortion, the study revealed the variance in immunological data in accordance with the term of pregnancy and cause of its incompetence. The lesser degree of immunological impairment was documented in the females whose pregnancy was complicated by hormonal disorders, whereas females with a history of infections in the early pregnancy demonstrated more profound immunological shifts. In those patients whose pregnancy was lost in the first trimester and the cause of the wastage remained unclear, the authors noted elevated T and decreased B lymphocytes, as well as dramatically reduced leukocyte migration inhibition factor.