By Sherifat Lawal
Bizarre but true, a set of twins, born from the same womb and on the same day can have different fathers.
As the world advances technologically, It is possible for a set of twins to have different fathers in a phenomenon called heteropaternal superfecundation, which occurs when two of a woman’s eggs are fertilized by sperm from two different men.
Heteropaternal superfecundation is most common amongst animals such as dogs, cats, and cows who have multiple mating with multiple males, it is quite uncommon amongst humans but it happens.
So, how does heteropaternal superfecundation happen in humans?
A woman naturally becomes pregnant because one of her eggs has been fertilized by sperm.
If that fertilized egg divides into two separate eggs, early in the pregnancy, it will produce identical twins.
On the other hand, fraternal twins occur when the woman simultaneously releases multiple eggs that become fertilized by different sperm from the same man.
In this case, the woman released multiple eggs within a week of one another. Within that narrow time frame, two eggs appear to have been fertilized by sperm; it will naturally produce fraternal twins.
But if the sperm is from two different men, it will produce fraternal twins with different fathers.
Still wondering how?
According to The Guardian (UK), there are two scenarios in which heteropaternal superfecundation can play out.
It has been medically proven that a woman can release two eggs at the same time.
Since sperm can survive for a few days in the female reproductive tract, loitering in the corner of the womb and the fallopian tube, it would be possible to have sex with one father-to-be in advance of the egg being released, and another just after ovulation.
The woman releases two eggs a few days apart but in the same reproductive cycle. Having sex with two different men during this period can result in heteropaternal superfecundation.
However, it is highly unlikely to happen in humans but it can happen as research has shown the occurrence of very few cases around the world.