Nobody knows what causes identical (monozygotic) twins. Everyone has the same chance of having identical twins: about 1 in 250.
What are my odds of having 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?
What are the odds of having back to back identical twins?
What are the odds of having a second set of identical twins? Having two sets of identical twins, while not unheard of, is rare. While your odds of having identical twins the first time is about 1 in 250, your odds of having a second set are 1 in 70,000.
Has anyone had two sets of identical twins?
The chances of having two identical sets of twins is extremely rare, and only happens in one in 111,111 pregnancies. Erin and Jake, who have six-year-old sons Cooper and Grant, were not trying to conceive when they realised Erin was pregnant once more.
Can you have identical twins more than once?
The National Organization of Mothers of Twins Clubs claims that once you have had fraternal (dizygotic) twins, your chances of having another set are three to four times greater than that of the general population. Both hereditary and environmental factors may contribute to this.
How rare is two sets of identical twins?
While its possible, having double twins (meaning two eggs split twice) is highly improbable. Identical twins count for just 0.4 percent of all births, or about 1 in 300. The chance of both of those eggs splitting twice is almost unheard of, although theres been at least one documented case.
Can identical twins be of different genders?
Identical (monozygotic) twins are always of the same sex because they form from a single zygote (fertilized egg) that contains either male (XY) or female (XX) sex chromosomes. A set of boy/girl twins: Can only be fraternal (dizygotic), as boy/girl twins cannot be identical (monozygotic)
Do twins come from mom or Dad?
For a given pregnancy, the odds of conceiving fraternal twins are only determined by the mothers genetics, not the fathers. Fraternal twins happen when two eggs are simultaneously fertilised instead of just one.