New Zealand's High Court on Wednesday took custody of an infant whose parents insisted that he only receive blood from donors who had not been vaccinated against the coronavirus, a demand the court said prevented doctors from performing a lifesaving surgery.

The 6-month-old boy, referred to as "Baby W" in court filings, has been diagnosed with a congenital heart defect and needs surgery to survive, according to the court order.

"He remains in urgent need of an operation, and every day that the operation is delayed his heart is under strain," the order said, citing one of his doctors.

Baby W's parents, Cole Reeves and Samantha Savage, had insisted that he could only be operated on if the blood used in the surgery came from unvaccinated donors. Doctors said that using blood donated from outside the normal channels was "impractical" for the situation and that doing the surgery without donated blood was "not an available option."

With time running out and the parents still objecting, Judge Ian Gault ruled that it was "in Baby W's best interests" for the court to take custody of him temporarily until the surgery could be completed.