Declining Vitamin K Shots Linked to Higher Infant Bleeding Risks

PHILADELPHIA, Nov. 5, 2026 /CourierPR/ -- Analysis of more than 5.2 million hospital births documents a dangerous national trend in the administration of intramuscular vitamin K to newborns, according to a study published in The Journal of the American Medical Association (JAMA). From 2017 through 2025, the percentage of infants not receiving the routine injection more than doubled, rising from 3.1% to 6.8% of newborns.

Researchers at Children's Hospital of Philadelphia (CHOP) analyzed deidentified electronic health record data from hospitals and clinics in all 50 states and Washington, D.C. The study included 5.2 million infants born at 35 to 43 weeks' gestation between 2017 and 2025 and followed them through their first six months of life. Of these infants, 234,825 (4.5%) did not receive the intramuscular vitamin K injection at birth.

The study found that infants who did not receive the vitamin K injection experienced more recorded bleeding events in the first six months of life than those who did. Specifically, 288 versus 186 bleeding events per 10,000 births were recorded. After adjusting for gestational age, sex, maternal characteristics, insurance status, and neighborhood-level measures, lack of documented vitamin K administration was associated with a 47% higher risk of any recorded bleeding event.

The difference was particularly concerning for bleeding in or around the brain, a potentially life-threatening complication. Babies who did not receive vitamin K had more than twice the risk of recorded intracranial bleeding, with 33 cases per 10,000 births compared with 13 per 10,000 among infants who received the injection. Death during hospitalization at birth in the presence of a bleeding diagnosis was also more common among infants without documented vitamin K administration.

The researchers estimated that for approximately every 114 newborns who did not receive the injection, there would be one additional bleeding event during the first six months of life compared with a similar group of infants who received it.

The study, led by Kristan Scott, MD, MSHP, currently an assistant professor at Emory University School of Medicine, was supported by a National Institutes of Health training grant (T32HD060550) and by the National Institute of Child Health and Human Development Grant (K23HD109426). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The findings were published in JAMA on November 5, 2026, with the DOI: 10.1001/jama.2026.21764.