Superfecundation: Woman Births Twins With Different Fathers In Rare Case
Twins being born with different fathers is an extremely rare occurrence known as heteropaternal superfecundation.
Women usually have to have sex with two different men within a day before or after ovulation for both eggs to be fertilised.
A rare case of twins born with different fathers has been reported in China after a DNA test was conducted, an indication she had been cheating on her husband.
The woman from China, who had a set of twin boys, but her husband took their children for DNA tests because of striking differences in their appearances.
It was gathered that the husband known by a pseudonym Xiaolong, had felt strange as he thought one of the boys didn’t look like him, and after they received the result, he had to question his wife over and over for her to tell the truth.
The result of the test, according to a report from a Chinese newspaper, led the new mother to admit that she had cheated on her husband in a one-night stand.
The story came to light when the couple, from south-eastern China’s Xiamen city, had to register the birth of their sons at the local police station early last year, according to Xiamen-based newspaper Strait Herald.
In order to complete the registration, the couple had to produce the results of a paternity test to prove that the babies were theirs. The husband had wondered why one of his sons didn’t look like him at all.
But he was still shocked upon receiving the DNA results, which claimed that one of the boys did not have any biological relationship with him, according to a director at the Fujian Zhengtai Forensic Identification Centre.
The centre arranged the paternity test for the couple. The director, Mr Zhang, said Xiaolong was furious after reading the DNA report and confronted his wife.
It is said that his wife initially denied having an affair, and accused her husband of falsifying the results. Xiaolong further interrogated his wife, who then admitted that she had slept with another guy. The father said he was happy to raise his own child, but not the one from someone else, the report said.
Experts say it is hard to calculate the exact odds of having twins with different fathers, but previous studies suggested the chance could be between one in 400 pairs and one in 13,000 pairs, according to The Guardian.
Similar stories have been reported in China before. In 2014, a rich businessman from eastern Yiwu city was devastated after discovering one of his twin sons was not his.
According to Sanxiang Urban Newspaper, the father, named Zhou Gang, decided to take his children for a DNA test after realising his elder son had double eyelids.
He said both he and the children’s mother had single eyelid, therefore he found it strange that one of the babies had double eyelids.
NOTE:
It may sound impossible, but twins being born with different fathers is an extremely rare occurrence known as heteropaternal superfecundation.
Cases typically only come to light when suspicious relatives request a DNA test of a newborn.
But one study suggests heteropaternal superfecundation may affect as many as one in 400 twin births in the US.
Heteropaternal superfecundation occurs when a mother releases two eggs that are then fertilised by two sperm cells from different men.
Women usually have to have sex with two different men within a day before or after ovulation for both eggs to be fertilised.
Although heteropaternal superfecundation is rare in humans, it is relatively common in other animals, including dogs, cats, cows and rodents.
In species where females have multiple partners, some males have even developed strategies to ensure their sperm reaches the egg.
This may include evolving penises that damage the female’s reproductive tract, preventing subsequent mating, as seen in dragonflies.
Source: The Conversation