A MEDICAL expert has said the genes provided by the natural parents make up an "extremely important" part of a child's identity, but other factors are also responsible.
Professor Andrew Greene, director of the Centre for Genetics based in Our Lady's Children's Hospital, Crumlin, since 1997, told the High Court that while a surrogate mother would "obviously influence" the development of a child, the genes provided through the sperm and egg of the natural parents made up a "major contribution" to that child's identity.
Prof Greene was speaking during a landmark legal action being heard by the family law division of the High Court, which will decide if a married couple who arranged for the wife's sister to act as surrogate for their children can be recognised as the twins' parents on their birth certificates.
The ova produced by the genetic mother was fertilised by sperm from the father and implanted in the surrogate mother, who then gave birth.
The surrogate mother supports the genetic parents' bid to be recognised as the parents on the girls' birth certs, with the couple claiming the State's refusal to do so is unlawful and in breach of their constitutional rights.
But the State is defending the case on the basis that the genetic parents cannot be recognised as the parents because of the "invariable and irrefutable rule" that the gestational mother – the woman who gives birth – is and must always be treated as the mother of the child.
Prof Green stood over a 2006 report from the Commission on Human Reproduction, of which he was a member, which recommended that a child born through surrogacy "should be presumed to be that of the commissioning couple".
While the science had changed since then, the "basic principles" still existed, he said.
"The gestational mother obviously does not carry a child who is her own genetic child," he said.
"The development of that child within her womb is something that she will obviously influence. So she is not simply a vehicle for carrying that foetus, she does have an effect on its growth and development."
However, he added: "One of the major factors in terms of determining who a person is, is their genetic parentage."
He agreed there were two reasons for the Commission on Human Reproduction's recommendations – the genetic link, and the intention.
"Do you quibble with the suggestion . . . (that) the people who provide the genetic material make by far the most important or the most significant contribution to the child becoming what they are?", counsel for the couple, Gerry Durcan, asked.
"It is a major contribution towards the development of the child, it is not the only contribution," Prof Greene said.
The case is being held in camera, and reporting restrictions are in place. However, redacted transcripts of the opening days of the case have been released.
Evidence was also heard from Dr Fionnuala Breathnach, an obstetrician at the Rotunda Hospital in Dublin, who said the make-up of the mother carrying the child influenced the development of the placenta, and that complications tended to arise from health issues of the mother.
The case continues today.