A Brazilian woman who gave birth to twins has declared that their paternities are different, after the result of the test.
The 19-year-old, who preferred to remain anonymous, took a paternity test to confirm the paternity of the twins when they were 8 months old. A DNA test for the man she believed to be their father only came back positive for one of the twins.
So, she started recalling past experiences and around the time the twins were conceived, she had sex with two different men on the same day.
The other father's test matched the second child's DNA sample.
Her doctor explains that it is a phenomenon known as heteroparental superfecundation.
"It is possible to happen when two eggs from the same mother are fertilized by different men. Babies have the same genetic material as their mothers, but grow in different placentas."
According to him, it is a "one in a million" event that he never thought he would encounter. It is thought that only 20 cases of twins not having the same father have been confirmed.
The children are now 16 months old, healthy and registered under the name of one of the fathers, who also helps their mother.