Studies link rising newborn bleeding to vitamin K shot refusals

Two studies of U.S. infant medical records found that vitamin K deficiency bleeding and other coded bleeding diagnoses have risen as the share of newborns without a recorded vitamin K injection increased. Researchers said the findings show an association, not that refusal caused every bleeding event. A JAMA study by Kristan Scott and colleagues examined records for 5,240,780 infants born at 35 to 43 weeks from 2017 through 2025. The share without a recorded injection more than doubled, from 3.1% in 2017 to 6.8% in 2025. By six months, coded bleeding diagnoses occurred at a rate of 288 per 10,000 infants without a recorded dose, compared with 185.9 per 10,000 among those who received one. After adjustment, the researchers estimated a 47% higher risk in the group without a recorded injection. The study also found that the adjusted risk of a coded brain bleed was 2.43 times higher among infants without a recorded dose. During birth hospitalization, deaths recorded alongside a bleeding diagnosis occurred at rates of 2.9 per 10,000 infants without a recorded injection and 1.1 per 10,000 recipients. Researchers cautioned that the records could not show whether bleeding caused those...