Association between morphine exposure and impaired brain development on term-equivalent age brain magnetic resonance imaging in very preterm infants

To investigate the relationship between morphine exposure in the first week of life and brain injury on term-equivalent age magnetic resonance imaging (MRI) in very preterm infants. A retrospective study included 106 infants with a birth weight of < 1500 g who were born at King Saud Medical City at ≤ 32 gestational weeks, were admitted to the neonatal intensive care unit, and underwent term-equivalent age or pre-discharge brain MRI. A univariate analysis in addition to modified log-Poisson regression with a robust variance estimator was applied, and the effect of early morphine exposure and cumulative dose in the first seven days on brain morphology and growth at term-equivalent age was determined using the Kidokoro score. Sixty-eight (64.2%) infants had received morphine in the first week of life (median cumulative dose: 1.68 mg/kg, interquartile range 0.48–2.52 mg/kg). Early initiation of morphine administration was significantly associated with high total white matter (adjusted relative risk [aRR] 1.32, 95% confidence interval [CI] 1.01–1.72) and cerebellum (aRR 1.36, 95% CI 1.03–1.81) scores and a small cerebellar volume (aRR 1.28, 95% CI 1.02–1.61). Morphine exposure in the first week of life was independently associated with white matter and cerebellar injury on term-equivalent age brain MRI in very preterm infants.