"Twin brothers but different fathers?"... A child born with a one in a million chance

Teenage Mother, "Slept with Two Men on the Same Day"
Cases of Overlapping Pregnancies During Pregnancy Also Reported

A woman in Brazil gave birth to twins with different fathers after having sexual relations with two men on the same day. This is a one in a million chance. Photo by Daily Mail

[Asia Economy Reporter Bang Je-il] In Brazil, a woman gave birth to twins with different fathers after having sexual relations with two men on the same day. This is a probability of about 1 in 1 million.

According to the Daily Mail on the 8th (local time), a 19-year-old Brazilian woman gave birth to twins last year. As the twins' first birthday approached, she requested paternity tests from the men she had sexual relations with to find out who the father was. The results showed that only one child matched the DNA of one of the men.

The woman’s attending physician, Dr. Tulio Jorge Franco, said in an interview with local media that this situation is a probability that occurs in about 1 in a million people, and only about 20 cases have been reported worldwide.

Dr. Franco explained, “Two eggs from the same mother were fertilized by different men,” adding, “The twin babies share the mother’s genetic material but grew in separate placentas.”

The woman said, “I remembered having sexual relations with another man and requested a paternity test from him as well, which also matched the DNA,” and added, “I never expected something like this to happen. The twins look very similar.”

Currently, the 16-month-old twins are reported to be cared for by one of the two fathers. The twins’ mother said, “He is helping take care of the twins and providing a lot of support. He is supporting everything the children need.”

Meanwhile, cases of twins with different fathers have already been a topic of interest once in the United States. In 2015, a man living in New Jersey, USA, confirmed through DNA testing that only one of the twins was his biological child.

At that time, the twins’ mother demanded child support for both twins from the man, leading to a legal dispute. The court ruled that the man only had to pay child support for the twin who was his biological child.

◆ Cases of superfetation, where a woman becomes pregnant again during pregnancy, also exist

Not only twins with different fathers but also cases of superfetation, where a woman becomes pregnant again while already pregnant, are known. All of these are rare occurrences.

In September last year, a woman in the UK gave birth to two children simultaneously at a hospital in Somerset, UK. Although they were born around the same time, they were siblings, not twins.

She confirmed through an ultrasound at 12 weeks of pregnancy that her first child, Noah, was in her womb. Later, during the third ultrasound, she was told that another fetus had taken a place in her womb.

At the time, medical staff thought the two children were twins, but after noticing that the second fetus was much smaller, they concluded it was a case of superfetation. The fertilization times of the two children were estimated to be about three weeks apart.

In 2016, there was also a case of superfetation involving a woman from Australia. She became pregnant with twins and then conceived another child 10 days later. One of the twins was miscarried early in the pregnancy, resulting in the birth of two children.

Superfetation, also called “heteropaternal superfecundation” or “superfecundation,” can be found in some animals. In humans, it is extremely rare worldwide.