To investigate the influencing factors of chorioamnionitis in pregnant women with full-term premature rupture of membranes (PROM) and its impact on maternal and infant perinatal outcomes.

The clinical data of 192 full-term pregnant women with PROM who delivered babies at Shougang Hospital of Peking University from January to December 2020 were reviewed.

Body mass index≥24, excessive weight gain, pre-hospital PROM, anemia, amniotic fluid index <8 cm, and PROM for more than 24 hours were identified to be high risk factors for chorioamnionitis in women with full-term PROM. Last white blood cell count before fever or delivery ≥12×10⁹/L, neutrophil percentage (NE%) ≥75%, and C-reactive protein (CRP) ≥6 mg/L differed significantly between PROM women with and without chorioamnionitis. NE% ≥75% and CRP ≥6 mg/L had higher sensitivity and negative predictive value in the diagnosis of chorioamnionitis. There were significant differences in cesarean section rate, delivery bleeding, puerperal infection/incision infection rate between women with and without chorioamnionitis. There were also significant differences in the incidence of perinatal fetal distress, neonatal hyperbilirubinemia, and neonatal infection between the two groups.

Chorioamnionitis seriously affects the maternal and infant outcomes. Women with PROM should be educated to manage weight before and during pregnancy and correct anemia during pregnancy. Proper treatment of pre-hospital PROM and ultrasound examination in the third trimester of pregnancy should be emphasized. Vaginal operation should be avoided and sterile operation should be implemented. Routine blood test and CRP examination are of great significance for the detection of subclinical chorioamnionitis. It is suggested that patients with PROM, especially those with high risk factors for chorioamnionitis, should regularly and dynamically monitor routine blood parameters and serum CRP levels.