For twins to have the same mother but different fathers is a rarity, but according to Professor Le Dinh Luong in of Vietnam, a recent case found just that. It’s the first case of bi-paternal twins in Vietnam — the eighth reported in the world as of 2011. The Guardian reported that Luong declined to provide more details about the family to protect their privacy, but an online Vietnamese newspaper said that a 34-year-old Hoa Binh man called for DNA tests after recognizing that his twins did not look alike.
Bi-paternal twins are possible when women’s eggs are fertilized by sperm from different men between one and seven days apart in an ovulation period. The twins were born on the same day and have the same sex.
Read the full story at The Guardian.