Effect of chorioamnionitis on postnatal growth in very preterm infants: a population-based study in Japan.

PURPOSE: There is growing evidence that preterm infants born to mothers with chorioamnionitis (CAM) have increased risk of various neonatal morbidities and long-term neurological disorders; however, the effect of CAM on postnatal growth remains insufficiently investigated. This study evaluated the effect of histological CAM on postnatal growth trajectories in very preterm infants using a nationwide neonatal database in Japan. METHOD: A multicenter retrospective study was conducted using clinical data of 4220 preterm neonates who weighed ≤ 1500 g and were born at < 32 weeks of gestation between 2003-2017 (CAM group: n = 2110; non-CAM group: n = 2110). Z-scores for height and weight were evaluated at birth and 3 years of age. Univariable and multivariable analyses were conducted to evaluate the effect of histological CAM on ΔZ-scores of height and weight during the first three years with a stratification by infant sex and the stage of histological CAM. RESULTS: Multivariable analyses showed that histological CAM was associated with accelerated postnatal increase (ΔZ-score) in weight (ß coefficient [95% confidence interval]; 0.10 [0.00 to 0.20]), but not in height among females (0.06 [- 0.04 to 0.15]) and not in height and weight among males (0.04 [- 0.04 to 0.12] and 0.02 [- 0.07 to 0.11], respectively). An interaction analysis demonstrated no significant difference in the effect of histological CAM on the ΔZ-scores of height and weight during the first three years between male and female infants (height, p = 0.81; weight p = 0.25). CONCLUSIONS: Intrauterine exposure to maternal CAM contributes to accelerated postnatal weight gain in female preterm infants during the first three years.

Impact of antenatal corticosteroids on subcortical volumes in preterm infants at term-equivalent age: A retrospective observational study.

OBJECTIVE: Antenatal corticosteroids (ACS) is a well-established treatment for women at risk of preterm birth that improves neonatal outcomes. However, several concerns have been raised regarding the potential long-term adverse effects of ACS on the offspring's developing brain. Here we investigated the association between ACS and subcortical segmental volumes in preterm infants at term-equivalent age. STUDY DESIGN: This retrospective observational study was conducted using the clinical data of preterm singleton infants born between 220/7 and 336/7 gestational weeks at Nagoya University Hospital in 2014-2020. Subcortical volumes of the bilateral thalami, caudate nuclei, putamens, pallidums, hippocampi, amygdalae, and nuclei accumbens were evaluated using an automated segmentation tool, Infant FreeSurfer, and compared between neonates exposed to a single course of ACS (n = 46) and those who were not (n = 13) by multiple linear regression analysis (covariates: postmenstrual age at magnetic resonance imaging, infant sex, and gestational age at birth). We compared each subcortical volume stratified by gestational age at birth (<28 vs. ≥28 gestational weeks). RESULTS: Multivariate analyses revealed significantly smaller volumes in the bilateral amygdalae (left, p < 0.03; right, p < 0.03) and caudate nuclei (left, p < 0.03; right, p = 0.04) in neonates with ACS. Significantly smaller volumes in these regions were observed only in neonates born at 28 weeks of gestation or later. CONCLUSIONS: ACS was associated with smaller volumes of the bilateral amygdalae and caudate nuclei at term-equivalent age. This association was observed exclusively in infants born at 28 weeks of gestation or later.

Intrauterine exposure to chorioamnionitis and neuroanatomical alterations at term-equivalent age in preterm infants.

PURPOSE: Infants born to mothers with chorioamnionitis (CAM) are at increased risk of developing adverse neurodevelopmental disorders in later life. However, clinical magnetic resonance imaging (MRI) studies examining brain injuries and neuroanatomical alterations attributed to CAM have yielded inconsistent results. We aimed to determine whether exposure to histological CAM in utero leads to brain injuries and alterations in the neuroanatomy of preterm infants using 3.0- Tesla MRI at term-equivalent age. METHODS: A total of 58 preterm infants born before 34 weeks of gestation at Nagoya University Hospital between 2010 and 2018 were eligible for this study (CAM group, n = 21; non-CAM group, n = 37). Brain injuries and abnormalities were assessed using the Kidokoro Global Brain Abnormality Scoring system. Gray matter, white matter, and subcortical gray matter (thalamus, caudate nucleus, putamen, pallidum, hippocampus, amygdala, and nucleus accumbens) volumes were evaluated using segmentation tools (SPM12 and Infant FreeSurfer). RESULTS: The Kidokoro scores for each category and severity in the CAM group were comparable to those observed in the non-CAM group. White matter volume was significantly smaller in the CAM group after adjusting for covariates (postmenstrual age at MRI, infant sex, and gestational age) (p = 0.007), whereas gray matter volume was not significantly different. Multiple linear regression analyses revealed significantly smaller volumes in the bilateral pallidums (right, p = 0.045; left, p = 0.038) and nucleus accumbens (right, p = 0.030; left, p = 0.004) after adjusting for covariates. CONCLUSIONS: Preterm infants born to mothers with histological CAM showed smaller volumes in white matter, pallidum, and nucleus accumbens at term-equivalent age.