What is "superfecundation"

Superfecundation \Su`per*fec`un*da"tion\, n. (Physiol.) Fertilization of two ova, at the same menstruation, by two different acts of coition.

n. the fertilisation of two or more ova by sperm from separate acts of sexual intercourse, which can lead to twins with different fathers

n. fertilization of two or more ova released during the same menstrual cycle by sperm from separate acts of coitus (especially by different males)

Superfecundation is the fertilization of two or more ova from the same cycle by sperm from separate acts of sexual intercourse. The term superfecundation is derived from fecund, meaning the ability to produce offspring. Heteropaternal superfecundation occurs when two different males father fraternal twins.

In common usage, the term superfecundation is often used instead of heteropaternal superfecundation. The terms are practically equivalent because, though superfecundation by the same father is thought to be a common occurrence, it can only be proven to have occurred with multiple fathers.