The concentration of amino acids in the mother’s blood remains unchanged and is not qualitatively different from the amino acid concentration of fetal blood at the end of pregnancy. The placenta (placenta) is capable of passing all amino acids except glutamic acid, aspartic acid, and cysteine to the fetus. For this reason, the amino acid content in the blood of the fetus exceeds the maternal one many times over. This fact is an indication that the steady-state balance of maternal metabolism is always biased in favor of the child.
In contrast to the amino acid spectrum, there is an increase in the absolute amount and concentration of plasma proteins in maternal metabolism as pregnancy progresses. In particular, the concentration of alpha-1 and alpha-2 globulin and transferrin increases due to the altered estrogen metabolism. Transferrin (iron stores) increases relatively early and reaches maximum levels within the 27th-40th week of pregnancy, increased by 1.5 to 2 times in contrast to non-pregnant women. This promotes iron absorption and maintains an adequate iron binding capacity. Within pregnancy, the level of albumins (plasma proteins) decreases, which causes a reduction in the total protein concentration. Thus, in addition to carbohydrate-rich foods, protein-rich foods are also important.
Up to the 6th month of pregnancy, the recommended protein intake is 0.9 grams per kilogram of body weight. From the 6th month, pregnant women should increase their protein intake to 1.5 grams per kilogram of body weight.
Animal protein, unlike vegetable protein, is of higher quality and better covers the protein needs of the human body. The different biological value is due to the essential amino acids contained in different quantities. Accordingly, at least 50% of dietary protein should be of animal origin to ensure adequate levels of essential amino acids. However, vegetable protein does not have to be dispensed with. The essential amino acids of animal and plant foods can be supplemented in such a way that an equally high biological value can be achieved. Favorable combinations are potatoes with egg or dairy products and cereals with egg, dairy products or legumes. If pregnant women do not take in enough essential amino acids through their diet, a protein deficiency will result that can significantly impair the overall and organ development of the fetus and cause permanent damage.
