A UK woman conceived a child after sleeping with two brothers — identical twins — within a four-day window. DNA testing confirmed that either man could be the biological father. Since identical twins share the same genetic sequence, no test can further narrow it down. The Court of Appeal confirmed this month that science cannot, and currently neither can the law: the paternity is one or the other, but "not possible to say which."
The court ruled that the brother on the birth certificate was "not entitled" to that registration — but stopped short of declaring him not the father. "The failure to prove a fact means that that fact is not proved," McFarlane wrote. "It does not mean that the contrary is proved."
The man named on the birth certificate lost parental responsibility pending further hearings. A lower court will decide whether one, both, or neither brother should hold legal parenthood over the child, whose identity the court has protected along with those of the twins and the mother. McFarlane noted that science may eventually develop a way to distinguish identical twins at the DNA level — but not yet.
Previously:
