How Identical Twins Are Produced?

To form identical or monozygotic twins, one fertilised egg (ovum) splits and develops into two babies with exactly the same genetic information. To form fraternal or dizygotic twins, two eggs (ova) are fertilised by two sperm and produce two genetically unique children.

How are identical twins formed?

Identical twins occur when a single fertilized egg splits into two. Identical twins look almost exactly alike and share the exact same genes. Most identical twins happen by chance. Fraternal twins occur when two, separate eggs are fertilized by two, separate sperm.

Can you cause identical twins?

The chances of having identical twins is relatively rare — around 3 or 4 in every 1,000 births. And while it may be obvious, identical twins are always the same sex, either both boys or both girls, at birth. Why? Well, they don't just look alike — they also share the exact same DNA.