Hormones are allocated to the placenta during pregnancy, causing the body mother numerous physiological changes that provide proper development of the fetus, preparing the body for the upcoming birth and feeding.

The nervous system of a pregnant rearranged so that subordinates the whole organism one goal - childbearing. In accordance with this place physiological changes in its basic systems. Warmly - vascular system during pregnancy carries a hard work, because the body actually appears "second" heart - Is the placental circulation. Here, blood flow is so great that every minute passes through the placenta of 500 ml of blood. Heart healthy women during

Pregnancy easily adapts to the additional load: increasing the mass of the heart muscle and cardiac output of blood. For meet evolving needs of the fetus for nutrients, oxygen and building materials in the mother begins to increase blood volume, reaching a maximum at 7 months of pregnancy. For 4000 ml of blood now in the body circulates 5300 - 5500 ml. If the heart healthy woman easily cope with such work, then pregnant women with heart disease, this load causes complications, which is why they in term of 27-28 weeks is recommended hospitalization in hospitals, where the medicine was prepared for the heart intensive work.

Blood pressure during pregnancy is almost unchanged. On the contrary, women with his promotion to or in early pregnancy, it is usually decreases in the middle of pregnancy, due to the decrease in tone peripheral blood vessels under the action of the hormone progesterone. However, 2-3 months before birth blood pressure in these pregnant women, as a rule, re increases.In young healthy women, it is within 100/70-120/80 mm Hg. Art. Upper figures show the pressure during the reduction of heart - it systolic blood pressure, lower - at the time of pause - is the diastolic pressure.