The unidentified sources said a Japanese family court ruled that the parents, whose identities were not reported, potentially placed the child's life in danger by refusing the blood transfusion on religious grounds, the Kyodo News said Monday.
The family court's ruling, which took less than a day for it to reach, was the result of a complaint filed by a child consultation center.
The center filed a request for the parents to lose custody of their child, whose name was also not reported, amid an allegation of child abuse over the transfusion decision.
The young boy needed the blood transfusion after being diagnosed with heavy bleeding from his digestive tract last summer, Kyodo said.
The news group said the boy fully recovered after receiving the transfusion following the court's ruling. The child was later returned to his parents' custody after the consultation center withdrew its custody suspension request.