November 10, 2026Updated November 11, 2026, 12:59 p.m. ET
More babies are suffering life-threatening hemorrhages as a growing number of parents in the United States refuse a shot typically given to reduce that risk, according to two new studies.
The studies, both published on November 5, found a sharp increase in the incidence of bleeding in infants, which coincided with more parents refusing the vitamin K injection at birth.
Because babies are born with low levels of the vitamin, they are more prone to serious bleeding, especially in the brain and gastrointestinal tract. A vitamin K injection within six hours of birth helps blood clot and has been a standard practice in the United States since 1961.
These are the first published, peer-reviewed studies investigating increased bleeding in infants and refusal of vitamin K injections over the past decade. The Centers for Disease Control and Prevention (CDC) does not track rates of vitamin K refusal or associated bleeding; However, in July, lawmakers urged the agency to start keeping such records after a ProPublica investigation found babies were dying after their parents refused shots.
The tendency of parents to refuse the birth vaccine has increased steadily over 10 years, particularly since the 2020 pandemic, but accelerated after Health Secretary Robert F. Kennedy Jr. was confirmed as a vaccine skeptic. Kennedy, once the head of an anti-vaccine group, made several changes to U.S. vaccination schedules and recommendations, including removing several from the list of childhood vaccines. A federal judge blocked some of those changes in March, a decision the Department of Health and Human Services vowed to appeal. In September, Trump signed an executive order “calling for more vaccine flexibility and research” and fewer childhood vaccinations, repeating unsubstantiated claims about vaccines without evidence.
Health experts say mixed messages about vaccination have left many parents doubtful about routine treatments like vitamin K, which is a vitamin injection and not a vaccine. Critics, including U.S. Sen. Angela Alsobrooks, have called on Kennedy to clearly state that vaccines are safe and effective and to encourage parents to get them.
The U.S. Department of Health and Human Services told Reuters on Nov. 5 that the CDC still recommends vitamin K shots for newborns, but declined to say whether the agency would begin tracking rates of vitamin K refusal or bleeding events.
What did the new studies find?
The first new study, published in JAMA Pediatrics, found that the percentage of newborns receiving a vitamin K injection increased from 97.7% in 2017 to 95% in 2025, based on medical records for about 11 million infants aged 6 months and younger. At the same time, the rate of hemorrhage due to vitamin K deficiency, or VKDB, has almost quadrupled. The authors noted that the bleeding rate in 2025 was about double that in 2024.
The second study, published in JAMA, examined 5.2 million records from the same period. It found that vitamin K refusal rates more than doubled, from 3.1% in 2017 to 6.8% in 2025, and that babies who did not receive it had a 47% higher risk of bleeding in the first six months of life.
They were also twice as likely to suffer a brain hemorrhage or die when hospitalized with a hemorrhage diagnosis. For every 114 newborns who do not receive the vaccine, an additional bleeding event occurs, the authors noted.
“As with childhood vaccination, vitamin K (prevention) could be a victim of its own success,” says the second study. “The rarity of VKDB risks leaving today’s families largely unaware of its serious consequences.”
Both studies claim to have found a correlation but have not established definitive causation.
Why do infants get vitamin K?
Since 1961, the American Academy of Pediatrics (AAP) has recommended a single injection of vitamin K at birth to protect against bleeding. All babies are born deficient in vitamin K, essential for blood clotting, and cannot form clotting factors or substances that help the body stop bleeding naturally.
According to the CDC, vitamin K deficiency can cause serious, life-threatening bleeding in infants up to 6 months of age. Normal food sources for newborns, including breast milk, do not contain enough vitamin K to prevent this deficiency during the first months of life.
A single injection given within hours of birth ensures babies receive enough essential nutrients to manage any potential bleeding in the immediate future. According to the CDC, newborns who do not receive a vitamin K injection are 81 times more likely to develop serious bleeding than those who receive the injection.
“It may be too late to wait to see if your baby needs a vitamin K shot,” the CDC webpage says. “Babies may bleed into their intestines or into their brains, where parents cannot see the bleeding to know something is wrong. This can delay medical care and lead to serious or even fatal consequences.”
Why are more and more parents refusing?
Vaccine hesitancy, medical misinformation and misconceptions about the risks associated with vitamin K injections are likely causes of declining vaccination rates, according to several studies and experts.
A December 2025 JAMA study found that between 2017 and 2024, the number of infants who did not receive the vaccine at birth increased from 2.92% to 5.18%, with the largest change occurring after 2020. Parents refusing the vaccine often expressed concerns about injection-related pain, potential side effects and doubts about its necessity, according to the study. Acceptance rates began to decline in 2019, the study notes, meaning that medical skepticism related to COVID-19 was not the only source of attitude change.
The JAMA Pediatrics study authors also noted that the increase in vitamin K deficiency and associated bleeding coincided with an erosion of confidence in public health following the pandemic, growing vaccine hesitancy, and growing parental skepticism about interventions on newborns.
“I think it’s kind of a general distrust of our country that has developed over the last 10 years or so,” Dr. Ivan Hand, director of neonatology at NYC Health + Hospitals Kings County, previously told USA TODAY. “I think it’s a combination of things. There’s been more emphasis on ‘natural’ birth and some parents thinking, ‘it’s not natural for my baby to get a dose of vitamin K at birth’. Plus trying to demedicalize the birth process and, I think, just a general distrust.”
A 2022 AAP policy statement, co-authored by Hand, found that parents’ refusal to vaccinate was associated with a lack of understanding of the need for vitamin K, a belief that it was unnecessary, concerns about injection-related pain, and concerns about the preservative in the formulation.
Some hesitant parents point to misinformation that has proliferated since a debunked 1990 study linking vitamin K to childhood cancer, while others believe a “natural” birth with minimal or no interventions was healthiest for their babies, according to the policy statement. Some people mistakenly believe the vaccine is a vaccine and express concerns consistent with vaccine hesitancy.
Births outside of a hospital setting and without a doctor were also associated with higher refusal rates, according to the AAP report. “Outside influences include friends, celebrities and even some medical professionals,” he says.
“In a way, we’re victims of our own success, that people don’t see this kind of bleeding anymore because almost all babies have had this injection,” Hand said. “But if we don’t get this right, we’re going to see more and more cases of babies with bleeding, and that bleeding can be very severe; about half of it can be related to a brain hemorrhage. So that’s a very concerning thing that’s easily avoided by babies who get vaccinated.”
Contributor: Julie Steenhuysen, Reuters
Gn Health
