The State has won by a six to one majority its Supreme Court appeal against a landmark ruling the genetic mother of twins born to a surrogate is entitled to be registered as their legal mother on their birth certificates.

The Chief Justice, Mrs Justice Susan Denham, said the issues in the case arose from radical developments in assisted human reproduction and were “quintessentially” for the legislature, not the courts, to address.

There was “clearly merit” in the legislature doing so as there was a legal “lacuna” about certain rights, especially those of children born via such arrangements. “Any law on surrogacy affects the status and rights of persons, especially children: it creates complex relationships and has a deep social content.”

In separate judgments, Mr Justice John Murray, Mr Justice Adrian Hardiman, Mr Justice Donal O’Donnell, Mr Justice William McKechnie and Mr Justice John MacMenamim agreed the appeal should be allowed while Mr Justice Frank Clarke dissented.

The case centred on twins born, using genetic material from their parents, to a surrogate, a sister of the genetic mother who cannot carry children due to a disability.

The Registrar of Births registered the genetic father as the twins father on their birth certificates, but refused to register the genetic mother because she was not the birth mother and said the surrogate must be registered as the legal mother. The genetic parents successfully challenged that in the High Court which ruled motherhood is based on genetic links.

The State appealed, arguing the High Court decision had “massive” implications, including for mothers who bore children using donated eggs, and citizenship and succession rights.

The Chief Justice said the core issue was the registration of a “mother” under the Civil Registration Act 2004. There was “no definitive definition” of “mother” in the Constitution and nothing in the Constitution to prevent development of appropriate laws on surrogacy.

A core aspect of the State’s argument was a reliance on the status of “mater semper certa est”, the woman who gives birth is the mother of the child.

The Chief Justice said the maxim “mater semper certa est” is not part of Irish common law and those words simply recognised a fact that, until scientific developments in assisted reproduction, the woman who gives birth to a child is the child’s mother.

Neither Irish common law, the Civil Registration Act 2004, the Status of Children Act 1987 or any other legislation addresses the issues which arise on surrogacy arrangements, she said. There was thus a lacuna in the law which was for the legislature, not the courts, to address and on that basis she would allow the appeal.

The Commission on Assisted Human Reproduction had recommended new legislation be introduced to establish an independent and regulatory body to regulate provision of assisted human reproduction here and that surrogacy come within the ambit of that body, she noted.

Mr Justice O’Donnell stressed his decision allowing the appeal was based on a narrow finding the 2004 Act requires the birth mother to be registered as mother on the twins’ birth certificates.

It was “completely wrong” a system which has not regulated assisted reproduction but permits children to be born via assisted reproduction fails to provide any system acknowledging the existence of a genetic mother not just for birth registration but for many other details of personal and family life recognised by the Constitution as “vital to the human person”, he said.

Mr Justice Hardiman said this was about the nature of motherhood and there was “a serious disconnect” between developments in embryology and the law which must be addressed via “an important policy decision”.

He was particularly concerned the High Court view of motherhood as based on genetic links would permanently exclude from the status of mother a woman who gave birth to children using donated eggs.

Mr Justice MacMenamin said, unlike this unique case, difficulties can arise with surrogacy arrangements and the need for legislation was clear since the mid 1990s. He considered the case could have returned to the High Court to consider if the genetic parents should be appointed the twins legal guardians prior to adoption. That would lead to the genetic parents, under Irish law, being regarded as the twins parents and the State had indicated the authorities would facilitate such an approach.

Mr Justice McKechnie said the genetic mother would have been destined to end her life childless were it not for the potentially life changing discovery of IVF. Her relationship with the children deserved recognition at Constitutional level, the State had not vindicated her rights and must urgently do so. The State’s failures meant she may not even have the right to apply for guardianship and to suggest she just adopt the children was “unacceptable”.

It was the legislature’s duty in the first instance to decide how her rights should be vindicated but, if it failed, there could be recourse to the courts. The outcome of his judgment was unsatisfactory, especially for the children and he considered it was “highly doubtful” these parents and children are a Constitutional family.

Mr Justice John Murray said there was a “manifest lacuna” in the law and it was “for the Oireachtas to make the value judgment based on best policy, as other countries have had to do, as to whether and in what cricumstances assisted reproduction by means of surrogancy should be permitted”.

Dissenting, Mr Justice Clarke said the genetic mother and birth mother both have some of the characteristics of mothers as that term is currently used in Irish law. He did not believe scientific advances meant a loss of status as “mother” for either a birth or genetic mother.

Pending the necessary legislation, he considered the “least bad solution” required a birth mother and genetic mother to be both registered in some way and the Registrar of Births should put measures in place for that. The court should declare the genetic mother the mother of the twins without prejudice to the status of the birth mother, he said.