U.S. newborn bleeding cases climb as more parents decline vitamin K shots, studies say

Rates of serious bleeding in U.S. infants have risen sharply in recent years as more parents refuse the protective vitamin K dose given to newborns, according to two studies that also link the trend to broader mistrust of vaccines and other newborn care.

The research is the first to connect increasing vitamin K refusals with rising bleeding rates among U.S. babies.

Newborns do not have enough vitamin K, which is needed for normal blood clotting, and injections at birth have been routine for decades. The U.S. Centers for Disease Control and Prevention does not monitor either vitamin K refusal rates or bleeding incidents.

Refusals have been increasing since the COVID-19 pandemic and have accelerated under Health Secretary Robert F. Kennedy Jr., who spent years spreading skepticism about vaccines before taking the nation’s top health job. He has since withdrawn childhood recommendations for six vaccines, and changes to the childhood immunization schedule remain on hold because of a legal challenge. Health experts say the mixed messaging has fueled doubts among parents about standard newborn treatments, including vitamin K.

A Health and Human Services spokesperson said the CDC still recommends vitamin K shots for newborns, but would not say whether the agency plans to track refusals or bleeding events.

A JAMA study published last December by Dr. Kristan Scott and colleagues at Children’s Hospital of Philadelphia found that more than 5% of U.S. babies did not receive a vitamin K shot in 2024, a 77% rise from 2017.

New findings published in JAMA and JAMA Pediatrics show that refusal rates have continued to rise and help connect the increase in refusals with more bleeding episodes.

Although the studies do not prove cause and effect, the parallel surge in bleeding and vitamin K deficiency is striking, said Dr. Steven Woolf, an epidemiologist at Virginia Commonwealth University whose work appeared in JAMA Pediatrics.

Vitamin K injections at birth have been the standard of care since 1961. “Now we’re stepping away from that and we’re seeing the consequences,” he said.

Woolf and his colleagues reviewed medical records for 11 million infants age six months or younger between 2017 and 2025. Over that period, the share of newborns receiving a vitamin K shot fell from 97.7% to 95%, while vitamin K deficiency bleeding nearly quadrupled and appeared to be speeding up.

Among more than 11 million births, the researchers identified 5,217 bleeding events during the study period.

“The rate in 2025 was approximately double what it was in 2024,” Woolf said.

The team said the 2025 peak coincided with weakening trust in public health after the COVID pandemic, rising vaccine hesitancy and greater parental skepticism about newborn interventions.

An exclusive Reuters analysis of more than 1 million births nationwide by health data company Truveta found that vitamin K refusals accelerated sharply in the first half of 2026, rising by more than 57% from January through June.

In Scott’s new JAMA study, researchers examined medical records from more than 5.2 million U.S. infants born between 2017 and 2025.

During that span, the proportion of newborns who did not receive a vitamin K shot more than doubled to 6.8% in 2025 from 3.1% in 2017, and also rose from 5.1% at the end of 2024.

Babies who did not get the shot had a 47% higher risk of bleeding in the first six months of life than those who did.

They also faced more than twice the risk of brain bleeding during those first six months, as well as death with a bleeding diagnosis during their hospital stay after birth.

The authors estimated that for every 114 newborns who do not receive the vitamin K shot at birth, one additional bleeding event occurs.

In June, Representative Kim Schrier of Washington and Senator Angela Alsobrooks of Maryland, both Democrats, urged the CDC to begin tracking these bleeding events.

Dr. Elizabeth Wolf, a pediatrician at Children’s Hospital of Richmond who led the VCU study, said the findings underscore the need for consistent public health messaging about vitamin K.

“Similar to the recent measles outbreaks, we are seeing the real-world implications of growing mistrust of doctors and public health professionals,” she said.