<div><span style="font-size: 1rem;">A Brazilian woman has claimed to have given birth to twins with different fathers after having sex with two men on the same day.&nbsp;</span><br></div><div><br></div><div>The anonymous 19-year-old, from Minerios in Goias, Brazil, explained that she took a paternity test because she wanted to confirm who the father was.</div><div><br></div><div>She had decided to get the test done because, after eight months, she had doubts about who the father was.</div><div><br></div><div>The 19-year-old collected DNA from the person who she thought was the father but, after two tests, the results only came back positive for one of the twins.&nbsp;</div><div><br></div><div>She then remembered that she had sex with a different man on the same day and when this second person took a test, it showed he was the second twin's father.</div><div><br></div><div>The phenomenon is scientifically named heteroparental superfecundation.</div><div><br></div><div>Speaking to Globo, her doctor Tulio Jorge Franco explained: 'It is possible to happen when two eggs from the same mother are fertilised by different men. The babies share the mother's genetic material, but they grow in different placentas.'</div><div><br></div><div>He emphasised that the case is extremely rare, and a 'one in a million' situation and he did not think he would see one like it in his life.&nbsp;</div><div>It has been claimed that there are only about 20 other cases in the world where this has happened.</div><div><br></div><div>Local media reported that the children are now 16 months old but Dr Franco only spoke about the case this week.&nbsp;</div><div><br></div><div>And now, one of the fathers looks after both children, giving their mother support.</div><div><br></div><div>It may sound impossible, but twins being born with different fathers is an extremely rare occurrence known as heteropaternal superfecundation.</div><div><br></div><div>Cases typically only come to light when suspicious relatives request a DNA test of a newborn.</div><div><br></div><div>But one study suggests heteropaternal superfecundation may affect as many as one in 400 twin births in the US.</div><div><br></div><div>Heteropaternal superfecundation occurs when a mother releases two eggs that are then fertilised by two sperm cells from different men.</div><div><br></div><div>Women usually have to have sex with two different men within a day before or after ovulation for both eggs to be fertilised.</div><div><br></div><div>Although heteropaternal superfecundation is rare in humans, it is relatively common in other animals, including dogs, cats, cows and rodents.</div><div><br></div><div>In species where females have multiple partners, some males have even developed strategies to ensure their sperm reaches the egg.</div><div><br></div><div>This may include evolving penises that damage the female's reproductive tract, preventing subsequent mating, as seen in dragonflies. - Daily Mail</div><div><br></div><div>bnbd24/fas</div>