First,I want to ask a question. Anybody here got a twin brother or sister?
I think most of us are singletons.It means we are single when we are in our mothers' bellies.
However,someone is unusual.
There are around 1 percentage people in the world having roommates
when they in their mothers' bellies.
If it has one roommate,they are twins. If it has two or more roommates, they are multiples.
We all know that there are two kinds of twins --- identical and non-identical twins.
Identical twins are formed from a single egg in the mothers’ body
which divides to form two separate babies.
Identical twins look the same,and are often dressed in clothes of the same colors.
It is often difficult to tell identical twins from each other,even they are standing side by side.
Non-identical twins come into being when the mother produces two separate eggs at the same time,
both of which grow to form babies. In this case the twins look like normal brothers and sisters
and are easy to tell one from the other.
Similarly, the multiples come into being in the same way.
If a single egg divides into three babies or a mother produce three eggs once,
then she will get a triplets.
How do you think about twins, triplets or even quadruplets?
Is it a good phenomenon? In fact,the rate of twins’ birthing is 1%
and of the triplets’ is 1‰ under natural condition.
However,with the development of assisted reproduction,more and more twins and multiples are born.
It sounds great. However, after China allowing a second child,
some people want another child in their mid-forties.In natural,they can’t get pregnant.
Then they get assisted reproduce treatment.To improve the survival of the eggs,
doctors usually put at least 2 eggs in the mothers’ body.
If over 1 egg survive ,there must be a twins or more .
However ,the middle-aged mothers are not suitable for containing two or more babies.
If she insists on twins, she will have a life risk.
So when you see a twins,they might have a great mother.