resulting in twins of slightly different ages. Different FathersIn heteropaternal superfecundation, two eggs released in the same cycle are fertilized by sperm from two different people.

Per the USA Today article of Washington’s case, some studies have shown that 1 to 2 percent of all fraternal twins have ...

Half-identical or polar body twins are born together. However, the mother’s egg splits in two and each half is fertilized by sperm from two separate males. This is called superfecundation.

One egg is fertilized by one man, another egg by the second man. This is called superfecundation. The Science of Fraternal Twins Mixed-gender twins are the most common type of fraternals ...