A clinical and microbiologic analysis of risk factors for puerperal endometritis

Predictors of postpartum endometritis were identified in 607 asymptomatic, laboring women. One hundred (16.5%) developed postpartum endometritis. Multivariate analysis using stepwise logistic regression identified cesarean delivery (relative risk 12.8; P <.0001) as the dominant overall predictor. In patients with cesarean delivery (N = 124), prophylactic antibiotics (relative risk 0.54; P <.0002) and high-virulence bacteria or Mycoplasma hominis (relative risk 1.4; P <.01) predicted the incidence of endometritis, and in patients with vaginal delivery (N = 483), “bacterial vaginosis organisms” (relative risk 14.2; P <.001) and aerobic gram-negative rods (relative risk 4.2; P <.01) predicted endometritis. Despite significant associations found on univariate analysis, clinical variables such as duration of labor, rupture of membranes, and internal monitoring were not predictive of endometritis in the multivariate analysis. Our findings show that cesarean delivery and certain organisms, such as bacterial vaginosis or highvirulence organisms, predict endometritis, and that clinical variables may be facilitators rather than predictors of endometritis.