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Asked by Elizzy to Bernerd on 5 Jul 2017.
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Bernerd Fulanda answered on 5 Jul 2017:
Dear Elizzy
In a multiple pregnancy, there is more than one baby growing in the womb (uterus) at the same time. Being pregnant with twins is the most common example. Having three babies in the same pregnancy is known as triplets, four is known as quadruplets. It is even possible to have more than four but it is very rare.
There are several ways in which this can happen. Firstly, the babies can be identical or non-identical.
Identical twins or triplets are called monozygotic. Mono means just one, and zygote means a fertilised egg. Therefore, monozygotic siblings (identical twins) come from one egg. In this case the egg has been fertilised by one sperm and then split into two or more embryos. These babies will all be the same sex. They will all have identical genes.
Non-identical twins are called dizygotic twins (or fraternal twins) may be triplets; more than 3 are polyzygotic. In this case each egg is fertilised by a separate sperm. The babies are not necessarily the same gender and they have different genes.
When an egg (or more than one egg) is fertilised, it becomes a zygote. It immediately divides into two cells and each of those cells then divides. This continues until there is a ball of cells which implants into the lining of the womb and becomes an embryo. Each embryo will develop into a fetus and then eventually become a baby.
Dizygotic (non identical) twins have their own placenta, amnion and chorion. So too do all other non-identical triplets or higher multiples. Each fetus develops separately in its own sac with its own blood supply. Each placenta may be separate or fused together.
In identical (monozygotic) pregnancies, however, this situation is more complicated. It depends on exactly when the zygote divided into two or more zygotes. There may be one placenta or more than one. If there is one shared placenta, this is called a monochorionic pregnancy
I hope you are now clear
regards
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Comments
Ken commented on :
Hi Elizzy,
Thank you for this question, it reminds me of my neighbours who are actually triplets, I really had rough time identifying them back in the days we liked playing Hide and seek.
Yes, is it possible for a woman to give birth to more than three children? This kind of giving birth to more than one child is called a multiple birth and this results from multiple pregnancy. Multiple births in humans and larger mammals are exceptional and may rarely occur .Such births are often named according to the number of offspring, for example twins, triplets and quadruplets.
Multiple pregnancy is experienced when a fertilized egg, which is referred to a zygote, split into more than two embryos. Embryo grows into foetus – and finally to a baby. If a fertilized zygote split into two embryos that results to twins, if it splits into three embryos that will be twins and if it splits to four , that will results to quadruplets. Foetuses that results from one zygote are identical where else foetuses from different zygotes are referred to as fraternal and don’t really look alike. This is because, fraternal share 50% of the genetic material while identical share 100% of the genes.
NB:
Did you know of the Dionne quintuplets?
Dionne quintuplets are identical sisters who were born in Canada in 1934 and they are known to be the first quintuplets to survive their infancy. All five survived to adulthood.
Dremy commented on :
i have liked the way the scientist have answered but i mostly appreciate the answer from Bernerd Fulanda