Examining each twin’s DNA will reveal whether they are identical or fraternal; fraternals also normally have separate amniotic sacs, as well as separate placentas. Are boy-girl twins always ...

That's why fraternal twins don't look identical, and can be boy/girl rather than just girl/girl or boy/boy. The majority of twins (70%) are fraternal. Learn your chances of having twins.

There are different types of twins, identical and fraternal being the most common. Identical, or monozygotic, twins develop from the same fertilized egg that splits into two. These twins are of ...