The Supreme Court has been told that twins born to a surrogate mother must have the genetic link with their ‘commissioning’ parents recognised.

On the second day of an ongoing appeal by the State against a High Court decision recognising the genetic mother as the legal mother of twins born to a surrogate mother, Gerard Durcan, Senior Counsel for the genetic mother and her husband, who is the genetic father, told the court that motherhood and fatherhood were determined by “inheritable characteristics” or a “blood link” to a child.

He rejected the argument made by Michael McDowell, senior council for the State, that recognising genetic mothers as legal mothers would lead to a flood of egg donors looking to be recognised as mothers. Mr Durcan said that this would not be a concern, as most egg and sperm donations are anonymous. The possibility that children would attempt to seek out their genetic parents was not raised.

Mr Durcan went on to outline his own set of ‘unintended consequences’ that would result from not recognising the genetic link between mother and child. He warned that genetic siblings, unaware of their relationship, could end up mistakenly marrying one another, or that a genetic mother could inadvertently marry her own son.

He argued that motherhood and fatherhood could be absolutely determined by genetic testing, and that this was the only practical way to preserve the legal principle mater semper certa est (‘the mother is always certain’).