Chorioamnionitis in pregnancy linked to increased asthma risk in preterm children
MedWire News: Children born prematurely to women who suffered from chorioamnionitis during pregnancy face a significantly increased risk for developing asthma, US research suggests.
“Chorioamnionitis, an inflammation of the maternal-fetal interface, complicates approximately 8% of pregnancies [and] more than half of preterm births are thought to be associated with histological chorioamnionitis,” explain Darios Getahun (Kaiser Permanente Southern California [KPSC] Medical Group, Pasadena) and team.
They add that although there is “persuasive evidence from studies based on animal models and human subjects that there is an association between chorioamnionitis and fetal lung injuries,” few studies have examined the relationship between chorioamnionitis and childhood asthma.
To address this, the team studied data on 397,852 singleton children born in KPSC hospitals between 1991 and 2007.
The researchers found that until 8 years of age there was a statistically significant difference in asthma incidence rates between preterm children (60.2 per 1000 person-years) and those born at full term (40.0 per 1000 person-years), regardless of exposure to chorioamnionitis during gestation.
However, the incidence rates of asthma in preterm children and those carried to term for pregnancies complicated by chorioamnionitis were 100.7 per 1000 person-years and 39.6 per 1000 person-years, respectively.
Further analysis revealed that children born at 23–28, 29–33, and 34–36 weeks' gestation after pregnancies complicated by chorioamnionitis were 1.23, 1.51, and 1.20 times, respectively, more likely to develop asthma than children of similar gestational age born to women who did not experience chorioamnionitis during pregnancy.
The researchers also found that the risk for childhood asthma associated with a preterm pregnancy complicated by chorioamnionitis was greatest among African Americans (hazard ratio [HR]=1.98), followed by Hispanics (HR=1.70), and Whites (HR=1.66). However, the association was not significant in Asian/Pacific Islanders (HR=1.15).
Getahun and team conclude in the Archives of Pediatrics and Adolescent Medicine: “Chorioamnionitis and preterm gestation may result in increased risk of childhood asthma, presumably in response to inflammation-mediated fetal lung injury and/or heightened immune response against subsequent encounters with pathogens.”
They add: “Our findings may provide clues to the role of a heretofore unrecognized component of the complex etiology of childhood asthma.”
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By Mark Cowen