Ever heard of "heteropaternal superfecundation"? It's an extremely rare phenomenon by which fraternal twins can be fathered by two different men. The term made headlines back in 2015 when a New Jersey ...

A man had to conduct a DNA test on his twin boys as required for an official documentation to confirm that both he and his wife are the parents of the twins. The test result came with devastating blow ...

Ovulation lasts 12 to 24 hours, during which an egg can be fertilized. The fertile window is six days long, including the day of ovulation and the five days before it. Understanding your cycle can ...