The clinical significance of microbial invasion of the amniotic cavity with genital mycoplasmas

OBJECTIVE: Mycoplasmas are the microorganisms most frequently isolated from the amniotic cavity of women with preterm labor and preterm premature rupture of membranes (PROM). Yet the clinical significance of microbial invasion due exclusively to these microorganisms is controversial. This study was conducted to determine the maternal and perinatal outcome of patients with PROM and microbial invasion with Mycoplasmas. STUDY DESIGN: Amniocentesis was performed in 108 patients with preterm PROM. Amniotic fluid (AF) was cultured for aerobic and anaerobic bacteria and Mycoplasmas. Patients were divided into three groups according to the results of AF culture: Group 1-patients with negative AF cultures; Group 2-patients with positive AF cultures limited to Mycoplasmas; and Group 3-patients with positive cultures for bacteria or mixed flora. Survival analysis was used to compare the duration of pregnancy among groups, RESULTS: 1) The prevalence of positive AF culture due exclusively to Mycoplasmas was 31.5% (34/108) and of positive culture with bacteria was 20.4% (22/108); 2) The amniocentesis-to-delivery interval in patients with positive cultures for Mycoplasmas was shorter than in those with a negative AF culture [medians: 24 (0.5-480) vs. 79 (5-1660) hours, p < 0.01], but not different than in patients with positive AF culture for bacteria; and 3) The prevalence of neonatal sepsis in patients with positive culture for Mycoplasmas was higher than in patients with negative AF culture [26.5% (9/34) vs. 7.7% (4/52), p < 0.5)], hut similar to that of patients with positive AF cultures for bacteria. CONCLUSIONS: I) Patients with preterm PROM and microbial invasion with Mycoplasmas had worse outcome than those with sterile fluid; 2) There was no difference in pregnancy outcome between AF infections caused by Mycoplasmas and those caused by other bacteria.