Chorioamnionitis

Chorioamnionitis, more precisely termed intra-amniotic infection, is infection and inflammation involving any combination of the amniotic fluid, fetal membranes, placenta, fetus, decidua, or umbilical cord. It usually develops when bacteria ascend from the lower genital tract, particularly after the protective barrier of the membranes has been disrupted. Ruptured membranes, prolonged labour, repeated vaginal examinations, and invasive intrauterine monitoring can increase the opportunity for ascending organisms to reach the amniotic cavity. The infection is often polymicrobial. It may begin without dramatic maternal illness, so the fetal heart-rate tracing and the character of vaginal or amniotic fluid can provide an early clinical signal. Inflammation releases cytokines and prostaglandins. These mediators produce maternal fever, accelerate the fetal heart rate, and can alter uterine contractility. The fetus is exposed to the same inflammatory environment, which raises the risk of neonatal sepsis, respiratory infection, and other complications of fetal inflammatory response. Maternal infection can also progress to uterine atony, postpartum infection, or sepsis. The practical consequence is that this is not an infection to observe while waiting for a culture result. Once the clinical pattern...