At a reception in a women’s consultation, the expectant mother must measure the pressure. Why is this indicator so important for the doctor, and how dangerous is high blood pressure during pregnancy?
Arterial pressure (BP) is the pressure exerted by blood on the walls of arteries. Its value is indicated in the form of a fraction, in which the first digit characterizes blood pressure at the moment of cardiac contraction (systole) – systolic, and the second indicates the amount of pressure at the time of heart relaxation (diastole) – diastolic blood pressure.
BP values are measured in millimeters of mercury, since initially the pressure was measured with mercury tonometers.
This parameter is one of the most important, characterizing the quality of the functioning of the body. Often during pregnancy, women first encounter the problem of increasing blood pressure, which can be dangerous for both the future mother and the fetus.
With an increase in blood pressure may appear:
- headache (its strength will be directly proportional to the level of blood pressure);
- noise in ears;
- a feeling of pressure on the eyes;
- general weakness;
- nausea and vomiting;
- redness of the face and chest area or appearance of red spots on the face;
- flickering flies before the eyes.
Insidiousness of high blood pressure pressure in pregnancy is that, in some cases, even with high BP figures, the patient does not feel any pathological symptoms, feels normal, continues normal daily activities. High blood pressure is detected by accident, with another appearance in the women’s consultation.
The absence of clinical manifestations of elevated blood pressure does not exclude the development of serious complications that can threaten the life of the mother and the unborn child, therefore it is very important to regularly monitor the pressure during pregnancy.
The parameters of blood pressure depend on many factors: the total volume of circulating blood, the vascular tone, the work of the heart (for example, the heart rate), the quality characteristics of the blood (viscosity, etc.), and also the level and activity of a number of hormones and biologically active substances, produced by the kidneys and adrenals, the thyroid gland, etc. In addition, a large influence on blood pressure exerts a number of external conditions: the level of physical activity, psychoemotional load, the magnitude of atmospheric pressure.
Considering that changes in the organism of the future mother occur concerning the amount of circulating blood, the work of the heart, changes in the hormonal background, even with a physiologically occurring pregnancy blood pressure varies depending on its term.
In the first and second trimesters, blood pressure, as a rule, decreases (systolic – by 10-15 mm Hg, diastolic – by 5-15 mm Hg), which is due to the action of the main pregnancy hormone – progesterone. It exerts a relaxing effect on the vessels, which is a prerequisite for the favorable growth and development of the fetus. As the gestation period increases, the cardiovascular load increases, as the volume of circulating blood increases (about 40% of the baseline: in the body of the expectant mother circulates 2-2.5 liters of blood more than before the onset of pregnancy), the frequency increases cardiac contractions (an average of 15-20 beats / min), production of placental hormones increases, the body weight increases significantly (by the end of pregnancy – in the norm of 10-12 kg).
This results in a slight increase blood pressure level, and it becomes as it was before pregnancy.
When complications develop pregnancy pressure can significantly increase, which is a potential threat to women and the future child. Therefore, from the moment of registration to the antenatal clinic, the amount and dynamics (change) of blood pressure are carefully monitored.
It is believed that the average BP, which can be considered optimal (that is necessary for life support of the body with a minimal risk of cardiovascular complications), is the level of systolic blood pressure 110-120 mm Hg. st., and diastolic – 70-80 mm Hg. Art.
The boundary values are 130 / 85-139 / 89 mm Hg. Art. If the blood pressure is 140/90 and above, then this condition is regarded as an arterial hypertension (pathologically high blood pressure).
It should be noted that among young women are often found those for which the usual pressure before pregnancy is BP 90 / 60-100 / 70 mm Hg. Art. In these cases, it is more correct to focus not on the absolute values of blood pressure, but on the increase in indicators: if the values of systolic pressure during pregnancy increased by 30 mm Hg. and diastolic – by 15 mm Hg. Art., then the future mother has high blood pressure.