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Vaccines aren’t the only thing slipping through the cracks for the nation’s youngest.
A growing number of parents are rejecting a routine treatment given to newborns shortly after birth — despite more than 60 years of medical recommendations.
Now, researchers are warning that the shift away from the decades-old practice is coinciding with a troubling rise in potentially deadly bleeding episodes among infants.
In a sweeping new study, researchers analyzed electronic health records for 5.2 million babies born across the US between 2017 and 2025, tracking them through their first six months of life.
They found that 234,825 infants — roughly 4.5% — had no documented record of receiving a vitamin K shot.
The injection is crucial because babies are born with very low levels of the nutrient, which is essential for blood clotting. They typically don’t get significant amounts from food until they begin eating solids, including leafy greens, around 6 months old.
That leaves a critical window when infants are vulnerable to vitamin K deficiency bleeding (VKDB), a rare but potentially fatal condition that can cause spontaneous internal bleeding.
Fortunately, a single vitamin K shot can prevent it. But without the injection, babies are 81 times more likely to develop VKDB.
The shot has been recommended for all newborns since 1961, according to the American Academy of Pediatrics (AAP).
The latest findings show just how much of a difference it can make. Babies without a documented vitamin K shot had 288 bleeding events per 10,000 births in their first six months, compared with 186 among those who received the injection.
Even after accounting for factors such as gestational age, sex, maternal characteristics and insurance status, researchers found that babies without the shot had a 47% higher risk of bleeding.
“The difference was particularly concerning for bleeding in or around the brain, a potentially life-threatening complication,” Dr. Kevin Dysart, senior study co-author and attending neonatologist at the Children’s Hospital of Philadelphia, said in a press release.
Babies who didn’t receive vitamin K had more than twice the risk of intracranial bleeding, with 33 cases per 10,000 births compared with 13 among those who got the shot.
Death during the birth hospitalization among babies with a bleeding diagnosis was also more common in infants without documented vitamin K administration, Dysart said.
The researchers estimated that for every 114 newborns who skipped the shot, there would be one additional bleeding event during the first six months of life compared with babies 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 Dr. Kristan Scott, the study’s lead author.
“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 growing number of parents turning down the vitamin K shot for their newborns comes amid growing distrust of public health recommendations, a trend that has picked up steam since the COVID-19 pandemic.
“I have families who think maybe this is a vaccine, but it’s very important to emphasize this is a naturally occurring vitamin that we all have and that we all need,” Dr. David Hill, a hospitalist, pediatrician and spokesperson for the AAP, told ABC News. “It has nothing to do with vaccines.”
The consequences of VKDB can be devastating.
The condition can cause severe bleeding in the brain or gut, unexplained bruising, seizures, vomiting blood and blood in the stool. In the most serious cases, it can lead to permanent brain damage or death.
About 1 in 5 babies who develop VKDB die. Among those who survive, roughly 40% suffer long-term neurological damage, including seizures or paralysis.
Perhaps most alarming, the majority of babies show no warning signs before the bleeding begins.
