Vietnamese Mother Gives Birth to Twins with Different Fathers

Scientists in Vietnam have confirmed a case of bi-paternal twins (twins with different fathers) after a couple who recently took their twin to a Center for Genetic Analysis and Technologies, for a DNA test in the country's capital of Hanoi.
The husband's relatives initially  noticed that one resembled him while the other didn't, urged the man to get the two year olds DNA tested, only for their suspicion to turn out to be true.

Le Dinh Luong, president of the Genetic Association of Vietnam said the family was surprised by the revelation, and looking for the best way to deal with the situation.

He told AFP:

"Our Centre for Genetic Analysis and Technology lab has tested and found a pair of bi-paternal twins, This is rare not only for Vietnam, but for the world."
"Bi-paternal twins can occur if two eggs from the same woman are fertilised by the sperm of two men during the same ovulation period.
The time window that eggs can be fertilised is small, with sperm cells capable of living inside a woman's body for only four to five days. The lifespan of a woman's egg, meanwhile, is just 12 to 48 hours" 

According to local reports, only one of the twin was biologically related to the father with both offspring of the mother - and the tests ruled out the possibility of a hospital mix-up shortly after their births.