Intraventricular hemorrhage (IVH) is a devastating morbidity in preterm infants and can result in poor neurodevelopmental outcomes. Intraventricular hemorrhage usually occurs within 72 hours after birth; post-acute-phase IVH (>1 week after birth) is uncommon. Development of the hemostatic system in fetuses and neonates is an age-dependent evolving process, and the neonatal hemostatic system is characterized by low levels of vitamin K-dependent factors, with further reduction caused by prematurity. Importantly, a severe coagulation deficiency can be a major contributing factor of IVH. Active maternal Crohn disease (CD) during pregnancy causes malnutrition via enteral malabsorption; this may include vitamin K deficiency, resulting in fetal vitamin K deficiency. We herein describe a preterm infant who was born to a mother with CD and developed post-acute-phase IVH due to coagulopathy despite vitamin K administration.