A woman who had sexual relations with two identical twins within a four-day window has been told by the Court of Appeal that it is impossible to determine which brother fathered her child.
In a complex legal case that highlights the limits of modern DNA testing, a family court judge has declined to remove the name of one twin from the child’s birth certificate, despite neither he nor his brother being able to be confirmed as the biological father.
The mother, who cannot be identified for legal reasons, had a relationship with both brothers around the time of conception. Along with one of the twins, she launched legal action after the other brother was listed as the father on the birth certificate. The pair sought to have the second twin legally recognised as having parental responsibility for the child, referred to in court documents as “P.”
A family court judge initially declined to amend the birth register, prompting the woman and the non-named twin to appeal to the Court of Appeal in London.
However, a panel of judges has now ruled that the truth of the child’s paternity remains binary. Due to the brothers being identical twins, standard DNA testing cannot distinguish which one is the father. While scientific advances may offer a resolution by the time the child reaches maturity, the court noted such testing currently comes at a “very significant cost.”
Sir Andrew McFarlane, sitting with Lady Justice King and Lord Justice Stuart-Smith, stated that it is “currently not possible” to say which man is the father.
Judge Madeleine Reardon, who heard the initial case, previously found that “both brothers had had sex” with the woman “within four days of each other in the month when P was conceived,” concluding that it was “equally likely that each of the brothers is P’s father.”
In his judgment, Sir Andrew ruled that the twin who was originally named on the birth register was “not entitled” to be registered as the father. Consequently, any parental responsibility he held “shall cease.”
Nevertheless, the judge stopped short of declaring that the named twin was definitively not the father.
“The failure to prove a fact means that that fact is not proved; it does not mean that the contrary is proved,” Sir Andrew explained. “There is a distinction between something being not proven, and making a positive declaration that the fact asserted is not true.”
The case is set to continue as the court hears further arguments regarding parental responsibility.
