In a very surprising turn of events, scientists in Vietnam have confirmed a case of bi-paternal twins, or otherwise twins who have different fathers.
A Vietnamese couple recently brought their fraternal twins to the Center for Genetic Analysis and Technologies, in the country’s capital of Hanoi, to have DNA tests, after pressure from extended family members who noticed the children did not look alike, said Le Dinh Luong, president of the Genetic Association of Vietnam.
The tests revealed a shocker: The twins have the same mother, but different fathers.
VNS, Vietnam’s state-run news agency, reported the family is from northern Hoa Binh province and the children are 2 years old. One sibling has thick and wavy hair, while the other has thin and straight hair, VNS said.
Twins who have different fathers are extremely rare, Luong said, adding this is the first case in Vietnam that he knows of.
It is estimated that there are about 10 sets of bi-paternal twins across the world, including one in Poland, one in Spain, two in India and two in the US
Last year a New Jersey man was ordered to pay child support for one girl in a set of twins, after genetic tests showed he was not the father of the other.
How are bi-paternal twins conceived?
Bi-paternal twins must be conceived through two acts of intercourse reasonably close together.
The lifespan of a woman’s egg is just 12 and 48 hours while a man’s sperm can survive between seven and 10 days.
The overlap between these times is when bi-paternal twins can be conceived.
