[Genital infections as a cause of abortion in the first trimester of pregnancy. Review of the literature].

The rate of spontaneous abortion from embryo-fetal infection is believed to range from 10 to 15%. This figure, however, is likely to be underestimated because of subclinical abortions occurring at the earliest stages of gestation that go undiagnosed. The actual frequency of infections resulting in 1st trimester spontaneous abortion is therefore unknown, whereas the impact of infectious agents in the TORCH group on the pathogenesis of such event is well known, although the pathogenetic mechanisms are not well understood. A wide range of microorganisms have been isolated by several investigators from the lower genital tract of women with 1st trimester spontaneous abortion. No causative relationship of HIV-1 infection to spontaneous abortion has been established yet. The diagnosis of abortion from infection can only be made retrospectively based on histologic examination of fetal and placental tissue and isolation on culture of the infectious agent assumed to have caused infection.