A controlled study of genital mycoplasmas in amniotic fluid from patients with intra-amniotic infection.

Amniotic fluid (AF) was collected via a transcervical, intrauterine catheter from 52 patients with clinical intra-amniotic infection (IAI) and from 52 matched, uninfected controls. The AF was cultured for Mycoplasma hominis and Ureaplasma urealyticum as well as for aerobic and anaerobic bacteria. Eighteen (35%) patients with IAI and four (8%) controls had M. hominis in AF (P less than 0.001). Twenty-six (50%) patients with IAI and 26 (50%) control patients had U. urealyticum in AF (difference not significant). In the AF specimens of patients with IAI, 15 (83%) of the 18 with M. hominis also contained greater than or equal to 10(2) colony-forming units (cfu) of a high-virulence bacterial isolate/ml (P less than 0.05). Within the limitations of the experimental design, U. urealyticum in AF is not associated with clinical IAI, whereas, with qualitative cultures, M. hominis in AF is. However, in IAI, M. hominis is isolated most commonly from the AF of patients with greater than or equal to 10(2) cfu of a high-virulence bacterial isolate/ml.