Why is preconception nutrition important?
Poor nutrition in late pregnancy affects foetal growth but after birth babies can usually catch up and the Central Nervous System (CNS) and brain development is not usuallyaffected. However, poor nutrition preconceptionaly, and in the early weeks of pregnancy, can affect the development of the embryo and its ability to survive. The CNS is particularly affected and both body and head circumference will be small.
Catch up growth is harder if the environment is not right during very early pregnancy and the bundle of cells that will become the baby is vulnerable.
The reasons for the vulnerability of the very early stage of pregnancy are as follows:
* There is rapid cell organisation, differentiation and organogenesis taking place at this stage. Poor nutrition will slow this down and/or disorganise it.
* Rapid cell doublings are taking place A "doubling" is the average rate of cell divisions of a large number of cells. Factors affecting the rate of cell replications have most of their effect during the first 6 weeks of pregnancy . Therefore even a small fall off in cell divisions in the early part of pregnancy can mean the difference between having a normal birthweight baby (NBW) or a LBW one
* Poor diet suffered while an egg is ripening, during ovulation, may lead to a damaged egg, usually as a result of oxidative free radical damage. Such a damage may give rise to congenital malformations in the offspring. A similar process could also cause sperm damage during its formation. Hence it is important to eat an anti-mutagenic diet especially during gamete formation. Fruit and Vegetables and wholegrain cereals are anti oxidising and thus prevent free radical damage
A poor diet by the mother during this time can cause a lower level of essential hormones as well as nutrients. Lack of essential nutrients causes a falling off in the number of cells For all these processes to run smoothly in the embryo there needs to be the right environment. At this early stage there is no placenta to concentrate nutrients or produce the correct level of hormones and prostoglandins Indeed, an optimum nutritional environment can even offset damage that some adverse agents might do such as drugs, alcohol, tobacco and heavy metalals