Why?

LIMITATIONS

During the time of pregnancy it is very important to know that the mother's diet and nutrition should be priority. Eating healthy and making sure you get the necessary and crucial nutrients needed is important, however, making sure the mother stays away from foods that can potentially be harmful to the baby is just as important. Foods like seafood are a great source of iron, protein and omega 3-fatty acids which can promote the development of the baby's brain but can also be harmful because of the amount of mercury in some seafood as well. An extensive amount of mercury in the baby's diet may result in damage to the development of the baby's nervous system. Swordfish, Tilefish, Mackerel, and Shark are fish that FDA encourages pregnant women to avoid during there term. Changes in the metabolism and circulation may increase the risk of bacterial food poisoning which essentially means the baby may get sick as well. To avoid this, the mother should be safe while preparing her meats and poultry correctly to avoid any food borne illness (ex. Listeriosis). Unpasteurized milk may also lead to food borne illnesses so this is a beverage the mother should completely avoid. Any caffeine that the mother decides to consume should be no more than 300 mg per day. Caffeine can cross through the placenta to the baby and affect heart and breathing rate much like it does to ourselves when we consume it. This can cause stillbirth, miscarriage and low birth weight. Alcohol is another important substance to avoid while pregnant. Even moderate consumption of alcohol can alter the baby's health: fetal alcohol syndrome, heart problems, mental retardation. Extensive intake of alcohol may even be fatal for the baby (8).

"Promoting optimal nutrition will not only ensure optimal fetal development, but will also reduce the risk of chronic diseases in adults" (8).

UNDERNUTRITION

Undernutrition in pregnant women may be when there are low amounts of necessary nutrient intake or may be the nausea and vomiting during pregnancy which is called hyperemesis gravidarum. This is a life threatening disorder and may even last till the sixteenth week of gestation. Early pregnancies and closely spaced pregnancies can also result in undernutrition. In teen pregnancies the mother and the fetus are competing for the nutrients because the teen is still growing whereas short intervals between pregnancies result in maternal nutritional depletion at the outset of pregnancy. Furthermore, lack of sufficient nutrients to the placenta results in reduced transfer of nutrients from the mother to the fetus which leads to undernutrition of the fetus.

OVERNUTRITION

Along with undernutrition, there can also be overnutrition. Overnutrition takes place when there is increased intake of energy and proteins. This can have a negative affect on fetal growth and increase the risk of neonatal mortality. Recent studies show the statistics of 65% of the U.S. adult population is overweight and 31% of the adult population is obese. Mothers who are overweight and overeat sometimes go into pregnancy and continue to overeat during gestation. This can result in restrictions on the growth of the fetus and an increased risk of neonatal mortality (9).

IMPORTANT NUTRIENTS

The placenta develops a connection between the fetal and maternal blood vessels that are in the uterine wall. The maternal blood exchanges oxygen and nutrients with the fetus's blood and picks up the fetus's waste. By doing so, the placenta performs the respiratory, absorptive, and excretory functions that the fetus's lungs, digestive system, and kidneys will provide after birth. The placenta is a metabolically active organ and it needs energy and nutrients to do the work it needs to do. This is why a healthy placenta is essential for the developing fetus to attain its full potential.

Each organ and tissue has its own critical period as far as proper development is concerned and during this critical period they are most vulnerable to undesirable influences such as nutrient deficiencies or toxins. Nutrients influence the development of diseases later on in adulthood. That is a process known as fetal programming. Simply having a certain gene does not ensure that the trait connected with that gene will be expressed because genes have to be activated. Nutrients play a key role in the activation of genes. In the case of pregnancy, the mother's nutrition can permanently change gene expression in the fetus as well. Much research is being done right now to determine which nutrients activate or silence which genes. So which nutrients are best during gestation?

Here are some important concepts and key nutrients pregnant humans need to take into consideration. The energy needs of a pregnant woman are greater than those of non-pregnant women. Pregnant women should consume an extra 340 k-calories throughout the second trimester and extra 450 k-calories during the third trimester. For an average 2000 k-calorie diet, these added k-calories add up to 15 to 20 percent extra more energy. Protein, essential fatty acids and other vitamins and nutrients are vital for the fetus.

Protein intake should increase by 25 grams. This can be accomplished by adding choice meats, dairy products and protein rich plant foods. The safest way to receiving this extra protein is solely from the foods you eat and not so much by supplements because taking supplements may be harmful during pregnancy. This extra amount of protein also helps build up the placenta as well. The requirements for high nutrient intake gives a bit more room for excess fat but it is the essential long chain polyunsaturated fatty acids that are particularly important to the development of the fetus. The brain is mostly made up of lipid material and it is dependent upon the long chain fatty acids such as omega-3