Formatting of Identical Twins
Many individuals are perplexed about the distinction between fraternal and identical twins unless they are well-versed in biology and conception. It involves more than just whether the two twins resemble one another.
Two eggs fertilized within the same ovulation window result in the development of fraternal twins (dizygotic) [1]. Contrarily, identical twins (monozygotic) [2] are created when a single egg divides into two separate embryos.
Even more specifically, identical twins come from the combination of a single egg and sperm. Fraternal twins, on the other hand, are the result of two distinct eggs being fertilized by various sperm.
As a result, fraternal twins are genetically distinct from identical twins. (Fraternal twins share the same genes as all other siblings who share the same biological parents).
The likelihood of identical twins occurring by coincidence outweighs the other two twin situations. Fraternal twin pregnancies can occur naturally, but they are more frequently observed in women who receive fertility treatments [3].
That’s because fertility medicines may boost the quantity of eggs released throughout a cycle, or several embryos may be placed back into the uterus through in vitro fertilization [4].