Investigating cerebral anomalies in preterm infants and associated risk factors with magnetic resonance imaging at term-equivalent age

Background: Being born very or extreme preterm is a major source of cerebral anomalies and neurodevelopmental disorders, whose occurrence depends on many perinatal factors. A better understanding of these factors could be provided by cerebral Magnetic Resonance Imaging (MRI) at term-equivalent age (TEA). Objective: To investigate, through cerebral TEA-MRIs, the relationship between the main perinatal factors, the occurrence of cerebral anomalies, and cerebral volumetry. Methods: We assembled a cohort of preterm babies born before 32 weeks of gestation who underwent a cerebral TEA-MRI. We assessed cerebral anomalies using a radiological scoring system -- the Kidokoro scoring -- and performed cerebral volumetry. We investigated the relationships between 9 clinical factors (birth characteristics, resuscitation treatments{\ldots}), Kidokoro scores, and brain volumes. Results: Among 110 preterms who underwent a cerebral MRI at TEA, only 6% suffered moderate-to-severe brain anomalies. We identified mechanical ventilation as a risk factor for cerebral anomalies (adjusted Odds-Ratio aOR = 4.6, 95% Confidence Interval CI [1.7-12.8]) and prolonged parenteral nutrition as a protective factor for white matter anomalies (aOR = 0.2, 95%CI [0.1-0.8]). Mechanical ventilation (p = 0.01) and being born small for gestational age (p < 0.001) were risk factors for the reduction of cerebral volumes. An increase in brain lesion severity was associated with decreased cerebral volumes (p = 0.016). Conclusion: Our study highlights the importance of treatment-related perinatal factors on the occurrence of cerebral anomalies in very and extreme preterms, and the interest in using both qualitative (Kidokoro scoring) and quantitative (volumetry) MRI-tools.