There are two kinds of delivery methods, one is natural delivery, the other is caesarean section, which is good, but caesarean section has certain randomness.
1, Shun gave birth to a child.
Suppose a pregnant mother gives birth to a baby in a natural way. If it is identical twins, it is two lives conceived by one egg, which are generally "rooted" in the mother at the same time, so it is meaningless to distinguish the size of identical twins. At this time, through the way of natural delivery, of course, the first one comes out, and the last one is the smallest.
2, caesarean section to produce children
If it is a fraternal twin, it is particularly random. It is very likely that the fertilized egg will be held out first, and the small one will become the boss; It is also possible that the fertilized egg will be fertilized first, and then he will be the boss.
When a baby is born by caesarean section, the size of the baby will be given to the doctor. I once met a friend who said she was the boss, but she always felt that her sister was more mature and developed faster than herself, and she wondered if the doctor "got" her out first.
Extended data:
The difference between fraternal twins and identical twins;
1, the difference in appearance
Generally identical twins are carved from the same mold, and sometimes even parents can't tell them apart. When I was a child, there might be an event where one was full and one was hungry. Of course, from a professional point of view, not only the appearance, but also many other details. Such as skin color, hairline height, hair color, including iris and so on.
2. The reasons are different.
As mentioned above, the formation process of fraternal twins, while identical twins are formed by a sperm and an egg. Only when the fertilized egg is produced, the fertilized egg splits into two, forming two embryos, but they come from the same chromosome and inherit the same gene.
The formation of fraternal twins is not only influenced by age and race, but also by medical means. Because in the treatment of infertility, doctors will use ovulation-promoting agents, so it is easy for women to expel two or more eggs, thus forming fraternal twins or triplets.
3. The probability of twins is different
Twins are generally divided into identical twins and fraternal twins. Identical twins account for about 1/3 of all twins, and fraternal twins account for about 2/3 of all twins.