Heteropaternal Superfecundation Posted at 5/24/2010 06:53:00 PM 0 comments (+) This note is about an interesting news story I just read...

Something about HETEROPATERNAL SUPERFECUNDATION... a genetic occurrence which is rare in humans and more common in animals. In short, it means having twins with different fathers! So how does that happen?

This is what my friend at Facebook thinks about this phenomenon.

A woman normally produces one ovum (egg cell) every month waiting to be fertilized. when a woman produces two ova, there is the tendency to bear twins when both eggs have been fertilized. However, after ejaculation, a man could possibly deliver only one healthy sperm to fertilize one of the eggs. And what if the woman had sexual intercourse with another man, is it possible that the other man's sperm could fertilize the other egg? The answer is YES. --- and that's how heteropaternal superfecundation happens!

In the news, a Turkish man suspects unfaithfulness towards his wife so he decided to have the twin brothers get DNA tested and the results revealed that he only fathers one of the boys. After such discovery, he opted to file a divorce. :( and that's their sad ending.


Heteropaternal superfecundation is very rare in humans, though more common in other animals (such as cats), and is extremely common in dogs, with stray dogs often whelping litters where every puppy is of a different father. This is primarily due to the predominance of 1:1 heterosexual partner pairings among humans. A woman who has sexual relations with two or more men at short intervals within the same ovulatory period can be impregnated by both men.

There have been noted examples in the past. The first recorded case was made by John Archer, an American physician in 1810 and is discussed in Williams Obstetrics (1980). According to Archer, a white woman who had sex with a black man and a white man within a short time subsequently gave birth to twins—one white, one of mixed-race. This is similar to some incidents of mixed twins. Other cases have been reported since, such as that of a Texas woman who gave birth to fraternal twins fathered by different men in June 2008.[2] In that case, a DNA test concluded that there was a 99.999 percent chance that the twins had different fathers. The twins' mother acknowledged having had intercourse with more than one man in a short period of time close to the conception date.

Labels: odd news buzz