The Supreme Court has been told parenthood cannot be conferred by agreement, as seven judges begin hearing an appeal by the State against a landmark High Court ruling on surrogacy rights.
The State is arguing that the woman who gives birth to a child is by definition the mother of that child.
Barrister Michael McDowell has told the court that this position is, and always has been, the law.
He has branded as "radically wrong" last year’s groundbreaking High Court ruling which found that the genetic mother of twins born to a surrogate could legally be described as the children’s mother on their birth certificates.
Mr McDowell claimed that a law based on genetics in which motherhood could be ascribed to the donor of an ovum could have massive consequences for succession, citizenship and criminal law.
He also said the High Court judgment created an anomaly whereby a pregnant woman considered the mother of an unborn child under the Constitution could cease to be that child’s mother after the birth.