Emicizumab prophylaxis in a preterm infant with severe hemophilia A: a case report on the feasibility of early use

Background Emicizumab provides effective prophylaxis for hemophilia A (HA), but evidence for preterm and very low-birth-weight infants remains limited. Key Clinical Question Can emicizumab be safely initiated shortly after birth in a preterm, low-birth-weight infant with severe HA? Clinical Approach We report a male infant born at 30 + 4 weeks of gestation to a known carrier of severe HA. Because of the high risk of intracranial hemorrhage, the case was reviewed by a multidisciplinary team with shared decision-making. After confirming severe HA and excluding intracranial hemorrhage on cranial ultrasonography, emicizumab prophylaxis was started at 26 hours of life, at a weight of 1.48 kg. Monitoring included emicizumab levels, thrombin generation, and inhibitor testing. The infant completed the loading phase and transitioned to maintenance dosing without bleeding, thrombosis, or adverse events. Conclusion This case supports the feasibility and early safety of initiating emicizumab in preterm, low-birth-weight infants.