The frequency and risk factors of funisitis and histologic chorioamnionitis in pregnant women at term who delivered after the spontaneous onset of labor

Objective. To examine the frequency and risk factors of funisitis and histologic chorioamnionitis in the placentas of term pregnant women who delivered after the spontaneous onset of labor. Methods. The frequency of funisitis and histologic chorioamnionitis was examined in consecutive pregnant women at term with singleton pregnancies who delivered after the spontaneous onset of labor. Nonparametric statistics were used for data analysis. Results. (1) The frequency of funisitis and histologic chorioamnionitis was 6.7% (88/1316) and 23.6% (310/1316), respectively; (2) Patients with funisitis had significantly higher rates of nulliparity, regional analgesia, operative vaginal delivery, longer duration of labor and rupture of membranes (ROM), and higher gestational age and birthweight than those without funisitis (p < 0.05 for each); (3) Patients with histologic chorioamnionitis had significantly higher rates of nulliparity, oxytocin augmentation, regional analgesia, cesarean section or operative vaginal delivery, longer duration of labor and ROM, and higher gestational age and birthweight than those without histologic chorioamnionitis (p < 0.05 for each); (4) Multiple logistic regression analysis indicated that the longer the duration of labor, the higher the risk of funisitis, and that nulliparity and the duration of labor significantly increased the odds of histologic chorioamnionitis (p < 0.05 for each). Conclusion. The longer the duration of labor, the higher the risk of funisitis and histologic chorioamnionitis in pregnant women at term who delivered after the spontaneous onset of labor.