Epidemiology and outcomes of pregnant trauma patients in Japan: a nationwide descriptive study

Purpose Trauma during pregnancy is the leading indirect obstetric cause of death, and its management is challenging owing to its characteristics. We aimed to describe the epidemiology of pregnant trauma patients and explore their characteristics by comparing them with those of non-pregnant patients. Methods Using the Japan Trauma Data Bank data collected between January 2004 and May 2019, we identified pregnant and non-pregnant female trauma patients between the ages of 15–45 years. We described patient characteristics, prehospital information, in-hospital management, and clinical outcomes. We also investigated the differences in the information between pregnant and non-pregnant patients. Results In total, 165 pregnant trauma patients were identified (0.7%). Motor vehicle collisions were the most frequent mechanism of injury (64.6%) in pregnant patients. The time from call to the arrival of emergency medical services at the hospital was similar for both pregnant and non-pregnant patients. The use of abdominal computed tomography (CT) scans was lower and injury to the abdomen was more frequent in pregnant than non-pregnant patients. In-hospital mortality was 7.2% in pregnant patients and 10.9% in non-pregnant patients. No significant differences in mortality after adjustment for confounding factors were found (adjusted odds ratio: 0.78, 95% confidential interval: 0.35–1.75, p = 0.548). Conclusion Transport time and mortality were similar between pregnant and non-pregnant trauma patients. Abdominal trauma and surgery were more common in pregnant relative to non-pregnant patients, while the number of CT scans was less. Further research is required to investigate the effects of trauma on the course of pregnancy and the fetus.