What is the difference between identical or fraternal multiples?
The zygosity of multiples may not be as simple as scientists once believed. While most multiples are defined as being either identical (mono-zygotic) or fraternal (di-zygotic) researchers and health care providers are still discovering and learning about an array of possible variations that include half-identical multiples, polar body multiples, and others. For the purposes of this question, we will focus on mono-zygotic and di-zygotic zygosities.
