Outcomes and risk factors of traumatic brain injury in infants under 3 months with minor head trauma: a retrospective study from a tertiary care center in Riyadh, Saudi Arabia

Diagnosing traumatic brain injury (TBI) after minor head trauma (MHT) in infants < 3 months is challenging; the applicability of PECARN is uncertain in this age group. To describe outcomes and risk factors for CT-confirmed (radiologic) TBI and clinically important TBI (ciTBI) in infants < 3 months with MHT. Retrospective cohort at a tertiary pediatric ED (Riyadh), Jan 2021–May 2025. Infants < 3 months presenting ≤ 24 h after MHT were included; suspected NAT was excluded. Primary outcome was radiologic TBI; secondary outcome was ciTBI. Because of sparse data, associations were estimated with exact (Fisher-based) univariable ORs in the CT-imaged subset. Of 77 infants, 23 (29.9%) underwent head CT; radiologic TBI occurred in 18/23 (78.3%; 95% CI 56.3–92.5%), predominantly isolated skull fractures, while ciTBI occurred in 2/77 (2.6%). Non-frontal scalp hematoma was strongly associated with radiologic TBI (OR 50.00; 95% CI 2.12–1178.94; p = 0.0017). Fall vs. not-fall was associated (OR 24.00; 95% CI 0.86–671.39; p = 0.040); fall distance ≥ 0.9 m was not significant (OR 2.33; p = 0.576). Most non-imaged infants met PECARN low-risk criteria. In infants < 3 months with MHT, non-frontal scalp hematoma is a high-yield marker for radiologic TBI, whereas ciTBI is uncommon. Findings support targeted imaging (when high-risk features cluster) and observation with safety-netting for otherwise low-risk infants, balancing potential benefit against radiation risk.