Growing numbers of parents are declining vitamin K injections for their newborns, placing infants at heightened risk of preventable brain injury, according to a preliminary systematic review.
A vitamin K injection is a routine supplement given to babies shortly after birth to address naturally low levels of the vitamin in newborns. It is not a vaccine.
Vitamin K is essential for blood clotting, and without sufficient levels, infants are at risk of developing a rare but serious condition known as vitamin K deficiency bleeding, which can cause an intracerebral haemorrhage, a form of stroke in which a blood vessel ruptures inside the brain.
The consequences can include lifelong neurological damage or death.
Dr Kate Semidey of Florida International University in Miami is a lead author of the review.
She said: “Vitamin K at birth is safe and effective, and while refusal is still uncommon with rates in the United States remaining under 1 per cent in most hospitals, our review found in recent years, there have been increases in parents refusing this supplement for their newborns.
“This trend is concerning because our review also found that babies who do not get the vitamin K injection are 81 times more likely to develop vitamin K deficiency bleeding.”
For the review, researchers analysed 25 studies drawing on two decades of global data, examining rates of vitamin K refusal, the incidence and outcomes of vitamin K deficiency bleeding, parental reasons for refusal, and possible links to broader vaccine hesitancy.
In Minnesota, refusal rates climbed from 0.9 per cent in 2015 to 1.6 per cent in 2019.
In California, Connecticut and Iowa, rates ranged from 0.2 to 1.3 per cent in 2018 and 2019, with more than half of hospital staff reporting a perceived increase.
Internationally, refusal rates ranged from one to three per cent in Canada, New Zealand and Scotland, and exceeded 30 per cent in some birthing centres.
Among case series reports of infants who developed vitamin K deficiency bleeding, the findings were stark.
Approximately 14 per cent of affected babies died, around 40 per cent were left with long-term neurological disabilities including cognitive impairment, seizures or motor deficits, and roughly 63 per cent experienced brain bleeds.
The review also found that parents who declined vitamin K for their newborns were considerably more likely to forgo other recommended health interventions.
In the United States, parents who refused the injection were 90 times more likely to also decline both the hepatitis B vaccine and the eye drops given to protect newborns from potentially blinding infections.
In Canada, those who refused vitamin K were 15 times more likely not to have their child vaccinated by the age of 15 months, and in New Zealand the figure was 14 times more likely.
Common reasons cited by parents included concerns about pain, the presence of preservatives in the injection, and exposure to inaccurate information.
“Our findings point to an urgent need for health care professionals to provide prenatal counselling to parents to ensure they understand that vitamin K can dramatically reduce preventable brain injury and its lifelong impact,” Semidey said.
The authors noted a key limitation: because the review drew on previously published research rather than following infants prospectively over time, it was not possible to determine the precise level of risk for any individual child.
