Further studies on genital mycoplasmas in intra-amniotic infection: blood cultures and serologic response.

Mycoplasma hominis is recovered significantly more often in amniotic fluid of women with intra-amniotic infection than in matched control women, but Ureaplasma urealyticum is found in 50% of amniotic fluid samples of both groups. To gain further understanding, we performed blood cultures for genital mycoplasmas and measured serologic responses by a micro enzyme-linked immunosorbent assay method in women with intra-amniotic infection and in control subjects. In blood cultures of 81 women with intra-amniotic infection, M. hominis was isolated in two (2.5%) and U. urealyticum in 11 (13.6%). In 44 control blood cultures, M. hominis was not isolated, and U. urealyticum was recovered in eight (18.2%). These differences were not significant. Serologic response was determined in 86 patients. Rise in antibody to M. hominis was significantly more common in women with intra-amniotic infection and M. hominis in the amniotic fluid than in either women with intra-amniotic infection or control patients without M. hominis. For U. urealyticum antibody response was significantly more common in the intra-amniotic infection group than in control subjects, but there was no association between antibody response and isolation of this organism in amniotic fluid. When M. hominis was found in amniotic fluid or maternal blood, patients were nearly always symptomatic. The high likelihood of serologic response in these cases supports a pathogenic role of M. hominis in intra-amniotic infection. The role of U. urealyticum remains unclear.