After getting pregnant, almost all mothers start reading various pregnancy proven tips on various aspects related to pregnancy and pregnancy symptoms. One widely searched question relating to pregnancy, which many mothers seek an answer to, is why their pregnancy lasts does for only nine months. New born babies are extremely weak and fragile. As a mother you wish that you could carry them a bit longer inside you so that they can grow stronger and then come out into this world. But unfortunately, even a healthy and fertile mother cannot, under any circumstances, carry her baby for more than nine months. There are two explanations, which have been given for this limited gestation period. The same have been discussed below:
Difficulty Fitting In The Birth Canal
The entire nine months of pregnancy can be divided into three trimesters. If we see the growth of the baby in each trimester we will be able to understand, why it is not possible to carry the baby for more than nine months. In the first two trimesters, the baby only takes a small form wherein the first trimester the cells develop, but the baby has no shape or identity, in the second trimester; it develops nose, chin, and forehead. By the end of these two trimesters the size of the baby is only about 3 inches in length. In the final third trimester, each and every body part of the baby develops and it weighs around 7.25 pounds, which is very difficult for the mother to carry as it is. If the baby is held any longer inside and it grows bigger in size, its head and hips would become so big that it would get stuck inside as the space in the birth canal would not be enough to push the baby out. Therefore, by the end of the ninth month, the baby needs to come out.
Pregnancy Eating Becomes Insufficient
Another important reason, because of which human pregnancy cannot be taken beyond nine months, is that during pregnancy, the mother does not eat just for herself, but also for the baby. All the energy demands of the baby have to be fulfilled by the mother. It is for this reason; a pregnant woman has to be extremely careful about her pregnancy diet. But as the baby grows in size, its demand for energy also increases and towards the end of the nine months, these demands reach a stage where it is not possible for the mother to eat any more, since the calories cannot be burnt by the body beyond that point. Therefore, the baby has to now come out and feed on its own. If the mother is forced to increase her diet any further, parental health would get compromised.
Over the years a lot of research has been done in this regard and most of the scientists today agree that the explanation of hip and head size ratio is not a very correct one. On the other hand, the explanation stating increased energy demands of the baby seems more correct.