A normal pregnancy implies overall average values of homeostasis and functional tests, typical of uncomplicated pregnancy in a healthy woman.
The changes proceeding in the body of a pregnant woman are programmed genetically; they are of physiologic adaptive nature. The range of these changes involving all the body's systems is determined by the necessity to promote fetal vitality and provide its protection; their extent is determined by the gestational age, the number of fetuses and individual reserve force of the mother.
2.1. METABOLIC CHANGES DURING PREGNANCY
In pregnant women metabolic processes are characterized by an intensified course. It is important that, alongside with activation of anabolic reactions, catabolism accelerates too, which is accompanied by increased excretion of metabolic waste products from the body. Furthermore, in the existing unique situation the drift of catabolic changes is aimed, in the first place, at providing chemical monomers for formation of complex macromolecular structures in the developing fetus.
All types of metabolic processes undergo substantial changes. This is connected directly with a change in the activity of numerous enzymes; this activity, in its turn, depends on the qualitative and quantitative balance between regulatory biomolecules (hormones, hormonoids, growth factors, cytokines and other).
Basal metabolism and oxygen consumption increase by 15-20% as early as by 16 weeks gestation reaching their peak values by the second half of pregnancy and during delivery (Fig. 2.1).
2.1.1. Protein metabolism
Protein metabolism becomes noticeably intensified. In the body of a pregnant woman nitrogen begins to be stored, which is necessary both for the mother and