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A Murine Model of Fetal Exposure to Maternal Inflammation to Study the Effects of Acute Chorioamnionitis on Newborn Intestinal Development
Published on: June 24, 2020
Histologic chorioamnionitis and fat mass accretion in infants born preterm
Emily Gunawan1, Viral G Jain1, Shakia Hardy2
1Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA.
Insights
Severe chorioamnionitis in preterm infants is linked to increased fat mass (FM) accretion by term-equivalent age. This association, independent of gestational age, may influence long-term body composition.
Area of Science:
- Neonatal research
- Perinatal medicine
- Pediatric endocrinology
Background:
- In utero insults, like chorioamnionitis, are linked to adverse infant outcomes.
- Chorioamnionitis is prevalent in preterm births and associated with increased risks.
- Understanding its impact on infant body composition is crucial.
Purpose of the Study:
- To investigate the association between chorioamnionitis and fat mass (FM) in very preterm infants.
- To analyze the impact of chorioamnionitis severity on FM accretion.
- To explore potential mediating factors in this relationship.
Main Methods:
- Retrospective cohort study of mother-infant dyads born before 32 6/7 weeks gestation.
- Infant FM measured by air displacement plethysmography at term-equivalent age.
- Chorioamnionitis severity assessed via placental pathology (MIR and FIR); analyzed using regression and mediation analyses.
Main Results:
- Infants exposed to chorioamnionitis (MIR) had significantly higher FM (kg and z scores) compared to unexposed infants.
- Severe maternal/chorion-amnion inflammatory response (MIR) correlated with higher body fat percentages.
- Gestational age partially mediated the association between chorioamnionitis and FM accretion (49%).
Conclusions:
- Severe histological chorioamnionitis is associated with increased fat mass accretion in very preterm infants at term-equivalent age.
- This effect appears independent of gestational age.
- Long-term implications of this early-onset difference in fat mass require further investigation.
Background:
In utero insults such as chorioamnionitis are associated with adverse outcomes. This study aims to examine the association between chorioamnionitis and fat mass (FM) in very preterm infants.
Methods:
We conducted a retrospective cohort study of mother-infant dyads born <326/7 weeks of gestation. Infant FM accretion was measured using air displacement plethysmography at term-equivalent age. Histological chorioamnionitis severity was staged based on placental pathology and included maternal/chorion-amnion inflammatory response (MIR) and fetal/umbilical cord inflammatory response (FIR). The association between chorioamnionitis severity and FM accretion was analyzed using linear regression models and mediation analyses.
Results:
Among 375 mother-infant dyads analyzed, 104 (28%) dyads had MIR. FIR was found in 85 dyads with MIR (82%). Infants without MIR had lower FM in Kg and lower FM z scores than those with MIR (p = 0.0001). Infants with severe MIR had higher body fat percentages (Stage 3: 18% vs Stage 1: 14%, p < 0.0001). There were no significant differences in other anthropometric growth rates. Gestational age partially mediated this association (49%).
Conclusion:
Severe histological chorioamnionitis is associated with greater FM accretion at term-equivalent age, independent of gestational age. Without long-term data, it remains unclear whether this early-onset effect is transient or persists into later childhood.
Impact Statement:
Chorioamnionitis is common in infants born preterm and is strongly associated with preterm birth. Infants born preterm exposed to chorioamnionitis have an increased risk of abnormal fat mass accretion at term equivalent age. Accounting for the severity of chorioamnionitis could improve the interpretation of body fat accretion in infants born preterm.
