During pregnancy a woman, as a rule, gives a lot of different tests. One of the important blood tests is biochemical analysis.
Biochemical analysis of blood allows you to evaluate the work of internal organs and body systems – liver, kidneys, the ratio of trace elements in the body, their lack and excess. Biochemical blood test is given strictly in the morning on an empty stomach, at least after an eight-hour fast.
Blood is taken from the ulnar vein. During pregnancy, biochemical analysis must be given twice – on registration and at 30 weeks of pregnancy.
At the early stage of pregnancy, that is, when registered with a women’s consultation, this blood test shows the changes in the body of a pregnant woman that existed before pregnancy, reveals chronic diseases and pathological conditions of various organs and systems of the body.
The study of blood biochemistry at 30 weeks shows how correctly a woman’s body adapts to the state of pregnancy, identifies malfunctions in adaptation processes and helps in the timely diagnosis of the pathological conditions that arise in the body of a future mother, allowing to prevent serious complications of pregnancy.
With various diseases of a pregnant woman, the frequency of the biochemical blood test can be varied, as well as the list of indicators to be studied. For example, in early toxicosis, liver enzymes and the electrolyte composition of blood (the concentration of microelements in it) are studied, in kidney diseases – protein, urea and creatinine, in diabetes – protein, liver enzymes, trace elements, glucose.
A standard biochemical blood test usually includes an assessment of the following indicators: total protein, bilirubin, glucose, ALT, AST, alkaline phosphatase, urea, creatinine, iron, calcium.
This is the most important indicator of protein metabolism in the body of a pregnant woman. Protein performs many important functions.
Pregnant women usually assess the total protein content. Normally, it is 64-83 g / l (you need to remember, however, that in some laboratories the normative values may differ slightly, which is due to the technology of performing the tests).
In the third trimester, there may be a slight decrease in protein concentration in the blood. The total protein of whey consists of a mixture of proteins with different structure and functions. With pronounced changes in protein content, certain groups of plasma proteins, albumin and globulins, can also be determined.
Albumin is synthesized, mainly in the liver, globulins – in the blood cells of lymphocytes. Their definition and correlation allows more accurate assessment of violations of internal organs.
A slight decrease in the level of protein (and physiological hypoproteinemia) is observed in pregnant women in the third trimester due to the so-called dilution of blood, that is, the increase in the volume of its liquid part – plasma, and also due to the increased use of albumin for the construction of the fetal tissues. In addition, the decrease in protein is noted with insufficient intake of it with food (for example, with malnutrition of the pregnant woman, with toxicosis of the first half), with intestinal pathology, liver, pancreas and kidney diseases, bleeding.
An increase in the amount of protein can be with dehydration, acute and chronic infectious diseases.
Of lipids (fats) in pregnancy, mainly determine cholesterol (cholesterol), sometimes triglycerides. Cholesterol is the most important indicator of lipid metabolism, serves as a structural component of cell membranes, participates in the synthesis of sex hormones, bile acids, vitamin D.
The cholesterol content in the blood largely depends on the age. The normal level of cholesterol in the blood of a young woman is 3.15-5.8 mmol? /? L.
During pregnancy, in the second and third trimesters, a physiological increase in the total cholesterol level to 6.0-6.2 is observed, which is due to the increased formation of cholesterol in the liver, as the need for it to build a vascular bed of the placenta and fetus, increased synthesis of hormones.
In the blood, cholesterol is in the form of highly soluble complex compounds with special transport proteins. Such complex compounds are called lipoproteins.
Reducing the concentration of glucose can be with liver diseases, dysfunction of the thyroid gland and other endocrine glands, diseases of the pancreas.
One of the important indicators of the biochemical blood test, which is necessarily evaluated in all pregnant women, is the pigment of the blood - bilirubin. Bilirubin is a bile pigment that forms as a result of decay hemoglobin - respiratory protein contained in erythrocytes (red blood cells).
In the breakdown of hemoglobin, initially formed free bilirubin, which is transported from the spleen to the liver in combination with the protein. Then in the liver, free bilirubin binds to a special acid (glucuronic acid), resulting in a direct, less toxic bilirubin, which is actively released into the bile ducts and is excreted with bile. Bilirubin is contained in the blood serum in the form of two fractions: direct (bound) and indirect (free) bilirubin, which together constitute a common bilirubin of blood.
During pregnancy, the determination of total bilirubin, direct and indirect, can be determined only if there are pathological changes in the level of total bilirubin. The normal level of total bilirubin averages 5-21 μmol / l, during pregnancy the bilirubin content usually does not change.
An increase in the concentration of bilirubin in the blood is noted in anemia due to accelerated decay of erythrocytes, a lack of vitamin B12. In this case, the increase in total bilirubin occurs mainly due to the free fraction. With liver diseases and blockage of the bile ducts, an increase in the level of total bilirubin occurs due to direct and indirect bilirubin.
With an increase in serum bilirubin concentration in excess of 27-34 μmol / l, jaundice appears - yellow coloration of the skin and sclera of the eyeball.
A reduced amount of bilirubin is noted with the use of a large amount of vitamin C, caffeine, certain medications.
In a standard biochemical blood test, it is necessary to evaluate the enzymes of the body - these are specific proteins that participate in various biochemical reactions as catalysts (substances that accelerate the reaction rate).
The main enzymes evaluated during pregnancy are ALT, AST, alkaline phosphatasebut, sometimes according to the testimony, investigate pancreatic alpha-amylase.
Alanine aminotransferase (ALT). It is a cellular enzyme that participates in metabolic processes. The maximum amount of ALT is contained in the liver and kidneys, so it is used to diagnose the damage to these organs.
The normal value of the content of this enzyme in the blood is up to 35 U / L and does not change during pregnancy.
Sodium - the most important element with which regulation of the distribution of water in the body is related. Normal concentration of sodium is 136-145 mmol? /? L.
In pregnant women in the second and third trimesters, the sodium level in the blood can be slightly increased - up to about 150 mmol / l. This is due to a delay in the body of pregnant sodium, potassium and chloride, which is due to the peculiarities of hormonal status and renal filtration.
Sodium participates in the mechanisms of excitation of nerve and muscle cells.
The increase in sodium in the blood occurs with a limited intake of fluid and an intensive loss of it, for example, with vomiting and diarrhea. Decreased sodium levels can occur with excessive abuse of diuretics, deficiency of thyroid function.
This can cause general weakness, lead to the development of various neurological disorders.
Potassium - the main intracellular microelement involved in metabolic processes, the formation of immunity, the transmission of nerve impulses in cells. The normal level of potassium in adults is 3.5-5.5 mmol / L, in pregnant women, potassium usually rises to 4.5-6.6 mmol / L by the end of pregnancy.
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