What are the different types of twins?
Are they identical? You’d be surprised how many times I get asked that question about my boy girl twins. Seriously. There is literally nothing identical about them and especially not their gender. I always chuckle when I get asked that question because you’d think the word identical would give it away.
Because this question comes up a lot I thought I’d share the different types of twins. This is great information to share if you keep getting asked what your twins are or if you’re expecting twins and curious about the differences.
Different Types of Twins
There are two main types of twins, identical and fraternal.
What are Fraternal Twins?
The most common type of twins, fraternal twins are also known as zygotic or having developed from separate eggs where each egg is fertilized by its own sperm cell. Fraternal Twins can be the same gender or different genders and have different physical characteristics because they didn’t share similar chromosomes.
What are Identical Twins?
Also known as monozygotic or paternal twins, identical twins develop from one zygote which splits and forms two embryos. Typically identical twins are the same sex and have the same hair and eye color.
Other types of twins include:
- Mirror Image Twins: Develop when they fertilized egg splits later than normal resulting in twins who went standing facing each other appear as matching reflections.
- Half-Identical Twins: When twins have identical genes from the mother’s side but different genes from the father’s side they are considered half-identical twins.
- Conjoined Twins: Extremely rare, conjoined twins develop when an early embryo partially separates to form two individuals that are usually attached at the chest, pelvis or buttocks.
Can Twins Have Different Fathers?
Yes, but it’s not very common. Known as Superfecundation, the eggs are fertilized during two different acts thus making the fathers of the twins different.
Can Twins Be Created At Different Times?
Yes, but this is also not very common. If a woman gets pregnant while already pregnant that results in two fetuses at different development stages, also known as Superfetation.
What type of twins do you have?