In just the third such court case in the country, a New Jersey judge has ruled a man is father to one twin while another man is father to the other. The children's mother named a man, identified as "AS," as the father of her twin girls, born in January 2013, when she applied for public assistance in Passaic County, the Star-Ledger reports. When she acknowledged that she'd had sex with another man within a week of her encounter with AS, a DNA test was conducted. It revealed what the New York Times calls "a tangled web of love and biology." AS had fertilized one egg with 99.9% certainty; the other was fertilized by the other man during the same menstrual cycle. Judge Sohail Mohammed ruled AS must pay child support for only the child he fathered, totaling $28 a week.
Mohammed noted he found just two court cases related to the phenomenon, known as superfecundation, NBC New York reports. But it's not quite that rare, per the New Jersey Law Journal. It references a 1997 article by identity testing expert Karl-Hans Wurzinger, who testified in this case, that put the number of reported paternity cases involving superfecundation at one in every 13,000. Indeed, the judge also said such instances are on the rise, citing factors like promiscuity, medically stimulated ovulation, and reproductive technologies (consider, for instance, a gay couple who both provide sperm and end up with twins). The ruling is "novel in that I don't think this issue was on anyone's radar to even question a client about," says a family law expert with the New Jersey State Bar Association. (When it comes to sex, here's how millennials' sex lives differ from their parents'.)