Association of post-cesarean delivery endometritis with colonization of the chorioamnion by Ureaplasma urealyticum.

OBJECTIVE: To determine if asymptomatic antenatal colonization of the chorioamnion with Ureaplasma urealyticum is a risk factor for the development of post-cesarean delivery endometritis.
METHODS: The chorioamnion was cultured at cesarean delivery for aerobic and anaerobic bacteria, mycoplasmas, Chlamydia trachomatis, and Trichomonas vaginalis in 575 singleton gestations with intact membranes. Culture results were compared with the clinical outcome. Postoperative endometritis was defined as a temperature of 38C with uterine tenderness and without other nonpelvic sources of fever.
RESULTS: Fifty-eight (10%) of the 575 women developed endometritis. Women with spontaneous labor developed endometritis twice as often as those delivered for medical or obstetric indications (17 versus 8%, P = .002). Endometritis occurred in 28% of women with U urealyticum present in the chorioamnion at cesarean delivery, compared with only 8.4% if the culture was negative and 8.8% if only bacteria other than U urealyticum were isolated (P < .001). Gestational age less than 34 weeks, spontaneous labor, and a vertical uterine incision were all associated with endometritis (P < or = .002). Regression analysis controlling for gestational age and incision type revealed a threefold increased risk of endometritis if the chorioamnion was colonized with U urealyticum at cesarean (odds ratio [OR] 3.0, 95% confidence interval [CI] 1.1-8.3) and an eightfold risk (OR 7.7, 95% CI 1.9-31.5) in women in whom the onset of labor was spontaneous.
CONCLUSION: Colonization of the chorioamnion with U urealyticum in women with intact membranes being delivered by cesarean is a significant, independent predictor of subsequent endometritis.