(Newswire.net — May 13, 2015) Paterson, NJ — A New Jersey mom who recently applied for child support, found out that the man she expected alimony from is the biological father to only one of her twin children.
The other baby, born at the same time has a different father, a DNA test confirmed.
It’s a phenomenon known to the medical community as heteropaternal superfecundation, meaning different father fertilization.
That does not mean that the woman had sex with two different partners at the same moment, but within the same week, because, once inside the uterus, sperm is viable for about five days.
According to Columbia University assistant clinical professor of maternal and fetal medicine Russell Miller, the phenomenon is not that rare. Miller told Business Insider, that the principle is the same as with twins who have one father.
Miller explained that with fraternal (non-identical) twins, two spermatozoids inseminate two eggs at the same time. It is possible that within a short period, one spermatozoid enters one egg and the DNA material from another male enters other egg cell. Those cells are growing normally, as any other.
In this case, simply two different sperm from two different male partners are fertilizing two eggs, Dr. Miller told Business Insider.
According to Dr. Miller, it is assumed that heteropaternal superfecundation is a rare phenomenon, but it’s hard to tell for sure, he said. The available statistics is based only on the cases brought to court when filiation is to be established by a paternity test.
for example, in 1992 a study found that amongst all the cases involving twins where one partner was questioning the paternity of another, superfecundation had occurred about 2.4% of the time, Business Insider reported.
Parents rarely do paternity tests in the first place, so it is impossible to determine commonness of superfecundation.
“The truth is nobody knows,” Miller says. “I mean we presume this is rare, but we don’t know at all.”