The High Court has given the parents of a four-year-old Down Syndrome boy with leukaemia until next month to seek expert advice over concerns about his prescribed treatment.
The HSE wants to continue the disputed treatment in the interests of the child.
The court heard the parents' objections to the leukaemia care were scientific rather than philosophical.
The HSE said that at this point the disputed treatment offered an 80% chance of life to the four-year-old boy, but that these prospects would diminish with time.
Senior Counsel Felix McEnroy told the court the parents were cooperative and had been through an agonising process, but he argued the risks of deferring treatment were unacceptable.
The boy's mother and father have agreed to resume the contested treatment in the event of a relapse.
President Nicholas Kearns has allowed the parents to address their medical concerns with international experts in the field but says a decision has to be made by May 3.