What Are Twins of Different Fathers
Twins of different fathers, also called heteropaternal superfecundation, happen when a woman releases two eggs during the same ovulation cycle. Each egg is fertilized by sperm from a different man, resulting in fraternal twins with different biological fathers. This is distinct from identical twins, which come from a single fertilized egg.
How Common Is Heteropaternal Superfecundation
Heteropaternal superfecundation is rare but documented. Studies suggest it may occur in a small percentage of fraternal twin pregnancies, especially when paternity is tested. A review of twin paternity cases found confirmed different-father twins in several percent of dizygotic twin sets where both fathers were identified.
How Different-Father Twins Are Confirmed
DNA paternity testing is the standard way to confirm twins of different fathers. Tests compare the genetic profiles of each twin with the alleged fathers. Because fraternal twins share about 50 percent of their DNA, like regular siblings, genetic testing can clearly show when each twin has a different biological father.
Learn more about twin paternity and superfecundation research.
