Introduction: Prophylactic low-dose paracetamol administration is used to induce closure of the ductus arteriosus. Effects on the neurological outcome in preterm infants remain unknown. We compared microstructural brain development in very preterm infants with and without exposure to prophylactic paracetamol by using MR-based diffusion tensor imaging. Materials and Methods: Infants aged <32 gestational weeks born between October 2014 and December 2018 received prophylactic paracetamol (10 mg/kg intravenously every 8 h until echocardiography after at least 72 h) and form the paracetamol group; infants born between February 2011 and September 2014 form the control group. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) at term-equivalent age were measured in 14 defined cerebral regions and compared between the groups. Results: Included in the study were 340 infants, of whom 217 received prophylactic paracetamol, and 123 formed the control group. The paracetamol group showed significantly higher FA values and lower ADC values in the splenium of the corpus callosum, as well as higher FA values in the pons bilaterally, the left middle cerebellar peduncle, the right occipital white matter, and the right posterior limb of the internal capsule (p ≤ 0.02). Conclusion: The perceived safety of prenatal paracetamol exposure has been questioned in recent years. We found no impairment on microstructural maturation processes in the brain of preterm infants at term-equivalent age following early paracetamol administration. The clinical relevance of these imaging findings has to be determined in long-term follow-up studies on neurodevelopmental outcome.

Introduction: Prophylactic low-dose paracetamol administration is used to induce closure of the ductus arteriosus. Effects on the neurological outcome in preterm infants remain unknown. We compared microstructural brain development in very preterm infants with and without exposure to prophylactic paracetamol by using MR-based diffusion tensor imaging. Materials and Methods: Infants aged <32 gestational weeks born between October 2014 and December 2018 received prophylactic paracetamol (10 mg/kg intravenously every 8 h until echocardiography after at least 72 h) and form the paracetamol group; infants born between February 2011 and September 2014 form the control group. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) at term-equivalent age were measured in 14 defined cerebral regions and compared between the groups. Results: Included in the study were 340 infants, of whom 217 received prophylactic paracetamol, and 123 formed the control group. The paracetamol group showed significantly higher FA values and lower ADC values in the splenium of the corpus callosum, as well as higher FA values in the pons bilaterally, the left middle cerebellar peduncle, the right occipital white matter, and the right posterior limb of the internal capsule (p ≤ 0.02). Conclusion: The perceived safety of prenatal paracetamol exposure has been questioned in recent years. We found no impairment on microstructural maturation processes in the brain of preterm infants at term-equivalent age following early paracetamol administration. The clinical relevance of these imaging findings has to be determined in long-term follow-up studies on neurodevelopmental outcome.