Can there be fraternal and identical triplets?
Like twins, triplets and other higher-order multiples can be categorized by their zygosity or degree of genetic similarity. Though triplets are most commonly fraternal (dizygotic or trizygotic), it is possible for triplets to be identical (monozygotic).
Are most triplets fraternal or identical?
Triplets can be either fraternal, identical, or a combination of both. The most common are strictly fraternal triplets, which come from a polyzygotic pregnancy of three eggs. Less common are triplets from a dizygotic pregnancy, where one zygote divides into two identical fetuses, and the other does not.
Can you have 3 identical triplets?
Turns out, they’re a very rare set of identical triplets. “They’re from the same egg, sharing the same placenta with three separate amniotic sacs,” said Bodgrog. “It’s so rare. There are hardly any case studies on it.”
Is it common for triplets to be identical?
It won’t surprise you to learn that identical triplets are rare: Doctors frequently call these births a one in a million occurrence. They’re actually more like a 20 or 30 in a million occurrence, according to research, but that’s still pretty nifty.
Can you have identical twins of different genders?
In 99.9% of cases boy/girl twins are non-identical. However, in some extremely rare cases resulting from a genetic mutation, identical twins from an egg and sperm which began as male (XY) can develop into a male / female pair.
How rare are twins and triplets?
Naturally, twins occur in about one in 250 pregnancies, triplets in about one in 10,000 pregnancies, and quadruplets in about one in 700,000 pregnancies. The main factor that increases your chances of having a multiple pregnancy is the use of infertility treatment, but there are other factors.
How common are fraternal triplets?
Fraternal triplets are more common than identical or monozygotic triplets. Around 80% or more of triplets are the fraternal variety. This is largely because most of the factors influencing other multiple births (such as twins), still play a part in conceiving non-identical triplets.
How common are identical triplets?
One in a million is commonly reported as the odds of having natural identical triplets, though estimates range from one in 60,000 to one in 200million.
How rare are triplets?
And a very rare one, too. The odds of identical triplets range from one in 60,000 to one in 200 million. But a widely reported figure, based on a study in the Journal of Biosocial Science, says that identical triplets occur about 20 to 30 times per 1 million births. While statistics are imprecise,…
How are identical triplets possible?
Identical triplets are possible because after the egg is fertilized, it splits into 3 parts. If the triplets were fraternal, three different eggs would have been released and fertilized by 3 different sperm, which is why fraternal triplets don’t have identical DNA.