Effect of chorioamnionitis on brain development and injury in premature newborns.
OBJECTIVE
The association of chorioamnionitis and noncystic white matter injury, a common brain injury in premature newborns, remains controversial. Our objectives were to determine the association of chorioamnionitis and postnatal risk factors with white matter injury, and the effects of chorioamnionitis on early brain development, using advanced magnetic resonance imaging.


METHODS
Ninety-two preterm newborns (24-32 weeks gestation) were studied at a median age of 31.9 weeks and again at 40.3 weeks gestation. Histopathological chorioamnionitis and white matter injury were scored using validated systems. Measures of brain metabolism (N-acetylaspartate/choline and lactate/choline) on magnetic resonance spectroscopy, and microstructure (average diffusivity and fractional anisotropy) on diffusion tensor imaging were calculated from predefined brain regions.


RESULTS
Thirty-one (34%) newborns were exposed to histopathological chorioamnionitis, and 26 (28%) had white matter injury. Histopathological chorioamnionitis was not associated with an increased risk of white matter injury (relative risk: 1.2; p = 0.6). Newborns with postnatal infections and hypotension requiring therapy were at higher risk of white matter injury (p < 0.03). Adjusting for gestational age at scan and regions of interest, histopathological chorioamnionitis did not significantly affect brain metabolic and microstructural development (p > 0.1). In contrast, white matter injury was associated with lower N-acetylaspartate/choline (-8.9%; p = 0.009) and lower white matter fractional anisotropy (-11.9%; p = 0.01).


CONCLUSIONS
Histopathological chorioamnionitis does not appear to be associated with an increased risk of white matter injury on magnetic resonance imaging or with abnormalities of brain development. In contrast, postnatal infections and hypotension are associated with an increased risk of white matter injury in the premature newborn.
Chau
Vann
V
Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.
Poskitt
Kenneth J
KJ
McFadden
Deborah E
DE
Bowen-Roberts
Tim
T
Synnes
Anne
A
Brant
Rollin
R
Sargent
Michael A
MA
Soulikias
Wendy
W
Miller
Steven P
SP
D016880:Anisotropy; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000254:growth & development / Q000473:pathology*; D001927:Brain Diseases / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology*; D002794:Choline / Q000378:metabolism; D002821:Chorioamnionitis / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007022:Hypotension / Q000453:epidemiology; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology*; D007239:Infections / Q000453:epidemiology; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D010920:Placenta / Q000473:pathology; D011247:Pregnancy; D011522:Protons; D012307:Risk Factors
D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate; D002794:Choline