Diagnosis and Management of Clinical Chorioamnionitis
Section snippets
Definition
Chorioamnionitis or intra-amniotic infection is an acute inflammation of the membranes and chorion of the placenta, typically due to ascending polymicrobial bacterial infection in the setting of rupture of membranes (ROM). Chorioamnionitis can occur with intact membranes, and this seems especially common for the very small fastidious genital mycoplasmas, such as Ureaplasma species and Mycoplasma hominis, found in the lower genital tract of more than 70% of women.1 Only rarely is hematogeneous
Epidemiology (incidence and risk factors)
Overall, 1% to 4% of all births in the United States are complicated by chorioamnionitis2; however, the frequency of chorioamnionitis varies markedly by diagnostic criteria, specific risk factors, and gestational age.3, 4, 5, 6, 7 Chorioamnionitis (clinical and histologic combined) complicates as many as 40% to 70% of preterm births with premature ROM or spontaneous labor8 and 1% to 13% of term births.9, 10, 11 Twelve percent of primary cesarean births at term involve clinical chorioamnionitis,
Mechanisms of chorioamnionitis and its associated complications
The pathogenesis of chorioamnionitis is marked by the passage of infectious organisms to the chorioamnion or umbilical cord of the placenta (Figs. 1 and 2).21, 22 This passage occurs most commonly by retrograde or ascending infection from the lower genital tract (cervix and vagina) (see Fig. 1). Hematogenous/transplacental passage and iatrogenic infection complicating amniocentesis or chorionic villous sampling are less common routes of infection. Anterograde infection from the peritoneum via
Clinical signs and symptoms
The key clinical findings associated with clinical chorioamnionitis include fever, uterine fundal tenderness, maternal tachycardia (>100/min), fetal tachycardia (>160/min), and purulent or foul amniotic fluid.2, 4
Maternal fever is the most important clinical sign of chorioamnionitis. Temperature greater than 100.4°F is considered abnormal in pregnancy. Although isolated low-grade fever (<101°F) may be transient in labor, temperature greater than 100.4°F persisting more than 1 hour or any
Clinical
As suggested by the name, clinical chorioamnionitis is diagnosed solely based on clinical signs because access to uncontaminated amniotic fluid or placenta for culture is invasive and usually avoided. Typically, the presence of temperature greater than 100.4° is required in addition to 2 other signs (uterine tenderness, maternal or fetal tachycardia, and foul/purulent amniotic fluid).2, 4, 26 Individual clinical criteria have variable sensitivity and low specificity for chorioamnionitis (Table 2
Summary
Chorioamnionitis is a common infection of pregnancy, typically occurring in the setting of prolonged ROM or labor. It may be diagnosed clinically, based on signs, such as maternal fever; microbiologically, based on amniotic fluid culture obtained by amniocentesis; or by histopathologic examination of the placenta and umbilical cord. Chorioamnionitis is associated with postpartum maternal infections and potentially devastating fetal complications, including premature birth, neonatal sepsis, and
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Cited by (601)
Clinical chorioamnionitis at term: definition, pathogenesis, microbiology, diagnosis, and treatment
2024, American Journal of Obstetrics and GynecologyPredicting peripartum infection in laboring patients at high risk in Cameroon, Africa
2024, European Journal of Obstetrics and Gynecology and Reproductive BiologyPre-labour Rupture of Membranes at Term in Women With Gestational Diabetes and the Risk of Neonatal Hypoglycemia
2024, Journal of Obstetrics and Gynaecology CanadaAssociation between intrapartum antibiotic prophylaxis for Group B Streptococcus colonization and clinical chorioamnionitis among patients undergoing induction of labor at term
2023, American Journal of Obstetrics and GynecologyAntibiotic treatment of women with isolated intrapartum fever vs clinical chorioamnionitis: maternal and neonatal outcomes
2023, American Journal of Obstetrics and Gynecology
Dr Tita was a Women's Reproductive Health Research Scholar supported by Grant No. 5K12 HD01258-09 from the Eunice Kennedy Shriver NICHD, National Institutes of Health at the time of manuscript preparation.