Infants Not Given Vitamin K at Birth Had Greater Bleeding Risks, Including in Brain

Swedish infants who did not receive intramuscular vitamin K administration at birth had an increased associated risk of bleeding episodes, including intracranial hemorrhage.Among more than 2 million live births from 2003 through 2021, infants who went without vitamin K had 1.52-fold higher odds of bleeding and 2.91-fold higher odds of intracranial bleeding during the first 6 months of life.Findings come as increasing trends of parental refusal of vitamin K prophylaxis at birth have been reported by several countries, the researchers noted.

Infants in Sweden who did not receive intramuscular vitamin K administration at birth -- a small but growing population -- had an increased associated risk of bleeding episodes, including intracranial hemorrhage, a nationwide cohort study suggested.

Among more than 2 million live births from 2003 through 2021, infants who went without vitamin K had higher odds of bleeding during the first 6 months of life compared with infants who received vitamin K (adjusted OR [aOR] 1.52, 95% CI 1.27-1.81), reported Eleni Simatou, MD, of Karolinska Institutet in Stockholm, and colleagues.

For intracranial bleeding, odds were 2.91-fold higher (95% CI 2.13-3.96) among those who did not receive the vitamin K shot, they reported in JAMA Pediatrics.