Fraternal twins are the most common type of twins and account for up to two-thirds of all twin births. Fraternal twins, often called “non-identical twins,” usually occurs when two eggs are fertilized at the same time by two different sperm. The two eggs form two zygotes, which explains why fraternal twins are referred to as dizygotic. They are no more alike than any other sibling. There is a genetic form for fraternal twinning, meaning that non-identical twins run in the family.
Identical twins occur when one egg is fertilized by a single sperm and the zygote then divides into two separate embryos within a few days.. How …show more content…
If the twin was far enough along, the doctor may induce the mother into early labour to give birth to the fetus that lacks nutrients and the other remains in the womb until full term. All cases of parasitic twins being attached externally are rare, there is an even more rare phenomenon that the twins may be absorbed and attached on the inside of the complete fetus. At first sight it was thought to just be a developed tumor inside the baby, after further examination it was proven to be the fetus’