A New Jersey father will have to pay to support only one twin after a judge found those twins have two different fathers.
The ruling came after a woman asked for child support for her twins. However, according to court documents, DNA testing determined the man originally cited as the children's father was actually only the biological father of one of them.
Because of that, Passaic County Superior Court Judge Sohail Mohammed ruled in family court on May 4 that the unnamed defendant would have to pay child support for the twin he fathered, and he dismissed the unnamed mother's claim for support of the other child.
Dr. Brooke Rossi, an obstetrician and gynecologist at University Hospitals McDonald's Women's Hospital in Cleveland, said while rare, having twins from different fathers can occur naturally.
The phenomenon can occur when a woman produces two eggs during her fertility cycle instead of one, and they can become fertilized and implant within a few days of the same cycle.
"The sperm live in the genital tract for two days," Rossi said. "It’s possible a woman can have sex with a man on a Tuesday and have sex with a different man on Wednesday, and it is possible for [her] to get pregnant," with twins.
The rare phenomenon is called heteropaternal superfecundation in medical literature. An estimated one in 13,000 paternity cases involves twins with different fathers, according to a 1997 medical journal cited in the court ruling.
Rossi said because fertilization would happen so close together, the fetuses would be the same gestational age and would be expected to be born without any related health complications.
In the New Jersey case, according to the court documents, the mother of the twins said in court she had sex with two different men around the time she conceived. However, she gave just one name in her petition for child support.
Karl-Hanz Wurzinger, laboratory director of the Laboratory Corporation of America, testified that he sees about six sets of heteropaternal twins a year in his lab.
Wurzinger could not be reached for comment.
While it's been a known phenomenon since the 1970s, according to court documents, there have been just two other reported legal cases of twins with different fathers in the U.S.