Declining Use of Newborn Vitamin K Shot Linked to Higher Risk of Infant Bleeding, Children's Hospital of Philadelphia Study Finds

Analysis of more than 5.2 million hospital births documents dangerous national trend in intramuscular vitamin K administration and underscores potential consequences for infants

PHILADELPHIA, Nov. 5, 2026 /PRNewswire/ -- In the largest retrospective study to date, researchers at Children's Hospital of Philadelphia (CHOP) found an increasing proportion of newborns are not receiving the routine intramuscular vitamin K injection at birth. The longstanding preventive treatment protects against dangerous bleeding in infancy. The research, published today in The Journal of the American Medical Association (JAMA), documented that from 2017 through 2025, the percentage of infants not receiving the injection more than doubled, rising from 3.1% to 6.8% of newborns.

Newborns receive an intramuscular vitamin K injection at birth to prevent vitamin K deficiency bleeding (VKDB), a rare but potentially life-threatening disorder. Because newborns have naturally low vitamin K, they may be unable to clot blood effectively, placing them at risk for severe bleeding, including intracranial hemorrhage.

"Routine intramuscular vitamin K administration has been highly effective at preventing vitamin K deficiency bleeding in newborns for decades," said Heather H. Burris, MD, MPH, one of the study's co-authors and an attending neonatologist at CHOP. "Our study is the first to document a nationwide decline in administration paired with increases in bleeding risks. Our findings underscore the importance of continued education and awareness, so families understand the serious, preventable bleeding risks for infants who do not receive vitamin K at birth."

Researchers 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 intramuscular vitamin K at birth.

Infants included in the study without documented vitamin K administration experienced more recorded bleeding events in the first six months of life than infants who received the injection – 288 versus 186 – per 10,000 births. 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," said Kevin Dysart, MD, a senior study co-author and attending neonatologist at CHOP. "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."

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.

"While bleeding risk increased for all babies over the course of the study period, the excess risk among infants without vitamin K was striking and present in every year of the study," said the study's lead author Kristan Scott, MD, MSHP, currently an assistant professor at Emory University School of Medicine who conducted this research when he was an NIH T-32 postdoctoral research fellow at CHOP. "The findings reinforce the longstanding recommendation that newborns receive the one-time intramuscular vitamin K injection shortly after birth and highlight the need to better understand why its use is declining."

The researchers were 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.

Scott et al. "Nonreceipt of Newborn Vitamin K and Risk of Bleeding." JAMA. Online November 5, 2026. DOI: 10.1001/jama.2026.21764.

About Children's Hospital of Philadelphia:  
 A non-profit, charitable organization, Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals, and pioneering major research initiatives, the hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country. The institution has a well-established history of providing advanced pediatric care close to home through its CHOP Care Network, which includes more than 50 primary care practices, specialty care and surgical centers, urgent care centers, and community hospital alliances throughout Pennsylvania and New Jersey. CHOP also operates the Middleman Family Pavilion and its dedicated pediatric emergency department in King of Prussia, the Behavioral Health and Crisis Center (including a 24/7 Crisis Response Center) and the Center for Advanced Behavioral Healthcare, a mental health outpatient facility. Its unique family-centered care and public service programs have brought Children's Hospital of Philadelphia recognition as a leading advocate for children and adolescents. For more information, visit www.chop.edu.

Contact: Amanda DiPaolo Bradley
Children's Hospital of Philadelphia
267-391-8599
[email protected]

SOURCE Children's Hospital of Philadelphia