Mycoplasma hominis and intrauterine infection in late pregnancy.

Amniotic fluid was collected via a transcervical intrauterine catheter from patients with clinical evidence of intrauterine infection and from uninfected comparison patients. The amniotic fluid was cultured for Mycoplasma hominis and Ureaplasma urealyticum, as well as for aerobic and anaerobic bacteria. Two series of patients are reported. In the first, there were 52 patients with intraamniotic infection and 52 matched controls. Eighteen patients (35%) with intraamniotic infection and four control patients (8%) had M. hominis in the amniotic fluid (P less than .001). Twenty-six patients (50%) with intraamniotic infection and 26 control patients (50%) had U. urealyticum in the amniotic fluid. In the second series, samples were collected consecutively. M. hominis was isolated from 32% (19/60) of specimens from patients with signs of infection and from 14% (8/56) of afebrile comparison patients (P less than .02). U. urealyticum was recovered from 43% and 39% of these fluids, respectively; the difference was not significant. When M. hominis was found in amniotic fluids of patients with signs of infection, the amniotic fluid usually contained greater than or equal to 10(2) cfu of a high virulent bacterial isolate per milliliter. Qualitative cultures showed that M. hominis in the amniotic fluid is associated with clinical intrauterine infection.