Vietnam - A woman has given birth to twins from two different fathers, after having sex with two different men in the same ovulation period, the Mirrorreports.
The Vietnamese couple decided to take their two-year old twins for a DNA test after striking differences in their appearances. They were astonished to find out that only one of the children were biologically related to the father.
The mother's husband was encouraged by relatives to pursue the DNA testing after only one of the children resembled him. It was later brought to light that the mother had sex with two different men during her ovulation period.
The Genetic Association of Vietnam says that these cases of bi-paternal twins is extremely rare and that the window period that a woman's eggs can be fertilised during her ovulation period only lasts four or five days only.
The twins, who were born on the same day and are the same sex, however have different appearances with one child having thick wavy hair, while the other has thin and straight locks.
The unidentified couple are said to be figuring out how to best deal with the shocking news.