This is when there are two eggs released by the mother. They are fertilized by 2 sperm. They are like siblings born at the same time. Except for being born at the same time, fraternal twins are no more alike than other brothers and sisters born to the same parents at a different time and place.
Fraternal twins can be either the same sex or opposite sex.
Inside the mother, fraternal twins are surrounded by separate sacs. They have separate placentas, although sometimes the placentas may grow together. Women who become pregnant soon after stopping the birth control pill. Women who have many family members with twins. Thirty percent of twins are identical.