Frozen embryos do not have a right to life, the High Court ruled today.
In a landmark decision, Mr Justice Brian McGovern found the term "unborn" refers only to a foetus or a fertilised egg implanted in the womb.
The judge insisted it was not the role of the courts to decide when life begins.
In a complex 26-page ruling, he found the constitution had made no provisions for the protection of embryos stored in fertility clinics.
"Laws should, and generally do, reflect society's values and will be influenced by them, but, at the end of the day, it is the duty of the courts to implement and apply the law, not morality," the judge said.
"Until the law or the constitution is changed, this issue remains within the sphere of ethics and morality."
Mr Justice McGovern went on to say it was a matter for the Oireachtas and the people by way of a referendum to decide when life begins.
The ruling comes as an estranged Dublin couple battle over the use of three frozen embryos stored in the Sims Fertility Clinic, Rathgar.
The High Court has already ruled the husband, who split from his wife after having an affair, did not give his consent for the eggs to be used in the event of their marriage breaking up.
Today's ruling is the second stage of the case, with the judge asked to consider public and constitutional law issues.
Mr Justice McGovern said all he can do as a judge is decide whether or not the frozen embryos have the protection of the constitution or the law.
"I cannot amend the law. That is the function of the Oireachtas," he said.
"Having considered the evidence and the submissions that were made and reviewed the law, I have come to the conclusion that the three frozen embryos are not 'unborn' ... and it is a matter for the Oireachtas to decide what steps should be taken to establish the legal status of embryos."