Chorioamnionitis is a common complication of pregnancy associated with significant maternal, perinatal, and long-term adverse outcomes. Adverse maternal outcomes include postpartum infections and sepsis while adverse infant outcomes include stillbirth, premature birth, neonatal sepsis, chronic lung disease and brain injury leading to cerebral palsy and other neurodevelopmental disabilities. Research in the last two decades has expanded our understanding of the mechanistic links between intraamniotic infection and preterm delivery as well as morbidities of preterm and term infants. Recent and ongoing clinical research into better methods for diagnosing, treating and preventing chorioamnionitis is likely to have a substantial impact on short and long-term outcomes in the neonate.
KeywordsChorioamnionitis; infection; pregnancy; management
DefinitionChorioamnionitis or intraamniotic infection is an acute inflammation of the membranes and chorion of the placenta, typically due to ascending polymicrobial bacterial infection in the setting of membrane rupture. Chorioamnionitis can occur with intact membranes, and this appears to be especially common for the very small fastidious genital mycoplasmas such as Ureaplasma species and Mycoplasma hominis, found in the lower genital tract of over 70% of women [1]. Only rarely is hematogeneous spread implicated in chorioamnionitis, as occurs with Listeria monocytogenes [2]. When characteristic clinical signs are present, the condition is referred to as clinical chorioamnionitis or clinical intraamniotic infection. Although there is significant overlap between clinical and histologic chorioamnionitis, the latter is a more common diagnosis based on pathologic findings on microscopic examination of the placenta that encompasses clinically unapparent (sub-clinical) chorioamnionitis as well as clinical chorioamnionitis. Funisitis, also a histopathologic diagnosis, is the extension of infection or inflammation to the umbilical cord. Overall the definition of chorioamnionitis a Corresponding author for proof and reprints: Dr. Alan T. N. Tita (alan.tita@obgyn.uab.edu Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Epidemiology (incidence and risk factors)Overall, 1-4% of all births in the US are complicated by chorioamnionitis [2]; 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 40-70% of preterm births with premature membrane rupture or spontaneous la...