Fraternal twins result from two eggs being fertilized at the same time, each by a different sperm.Each has its own placenta, and they can be the same sex or not.

• 而异卵双胞胎则是两个卵子同时受精，各自拥有不同的精子，每个受精卵都有各自的胎盘，其性别可能相同也可能不同。