Clinical and laboratory features during pregnancy

Anemia during pregnancy

According to WHO, approximately half a billion women of reproductive age in the world suffer from anemia. According to Rosstat, the course of pregnancy is complicated by the development of anemia in every third patient.

“You’re doing well, but your hemoglobin is a bit low.” - Oh, is that scary? - No, it’s not scary at all. I'll prescribe you a pill, and everything will be fine.

In fact, not everything is so simple - issues of iron deficiency are under the close attention of WHO experts, who recommend considering iron deficiency anemia as a significant risk factor for the death of children in the perinatal period.*

"I have low hemoglobin"

The norms of hemoglobin content in pregnant women differ from the population. From 1972 to the present, during pregnancy, the lower limit of normal for pregnant women is considered to be 110 g/l.

— My hemoglobin was 99 g/l, I took the drug, and after a week my result was 112 g/l. Tell me, doctor, should I continue taking the drug or is it enough?

Cases of “magical” healing are not uncommon. In such situations, it is important to understand how the study was conducted. Unfortunately, in the Russian Federation, a general blood test is still taken “from a fingertip”; the hemoglobin concentration is determined manually, using the obtained capillary blood samples. With this sampling technique, the hemoglobin level can be significantly reduced due to the presence of tissue fluid (the finger was massaged well or pressed hard). The maximum error can be obtained in pregnant women with edema - on average ±10 g/l.

The most accurate results are obtained from an automated venous blood analysis result. This is the method that should be used in everyday practice.

“We treat hemoglobin with iron”

Of course, you want to minimize drug exposure during pregnancy. Moreover, iron supplements are not always well tolerated - nausea, constipation, or diarrhea do not add loyalty to therapy even for the most disciplined patients.

— My hemoglobin is 110 g/l. During the consultation, the gynecologist insists on taking iron supplements, but the therapist says that it is too early. Who is right?

The one who makes the correct diagnosis will be right. A low hemoglobin level requires confirmation of iron deficiency, since anemia can be associated with various factors, and we only treat iron deficiency with iron supplements.

The “gold standard” for diagnosing iron deficiency is to determine serum ferritin levels. Even with a normal number of red blood cells, “good” hemoglobin and hematocrit, a ferritin level of less than 30 ng/ml clearly indicates latent (hidden) iron deficiency. It is at this moment that it is necessary to provide iron subsidies in a prophylactic dose in order to prevent a full-blown anemia. Prophylactic doses of iron are usually well tolerated and can be included in vitamin and mineral complexes.

Physiological changes in blood parameters during pregnancy

Changes in coagulogram and clinical blood test parameters.
Changes in the coagulogram
(No. , , , , 190, 164, 194)* of a pregnant woman are a physiological process associated with the appearance of the uteroplacental circulation.
This process is associated with the evolutionary, adaptive reactions of the body of a pregnant woman. A woman’s body prepares for costs during pregnancy and possible blood loss during childbirth. During the physiological course of pregnancy, the activity of the procoagulant link increases. Already in the 3rd month of pregnancy, fibrinogen increases (this is factor I (the first) of the plasma coagulation system) and reaches its maximum values ​​on the eve of childbirth. Therefore, gynecologists reasonably recommend monitoring this indicator during pregnancy (once per trimester, if there are deviations in these indicators, more often, once a week). At the end of the third trimester of pregnancy, the concentration of fibrinogen in the serum increases, which may correspond to an increase in the processes of intravascular coagulation in the uteroplacental bloodstream. Simultaneously with the increase in fibrinogen and the activity of the external coagulation pathway, the activity of the internal blood coagulation mechanism also increases, and a shortening of the aPTT is noted. Other parts of the hemostatic system also change during pregnancy, such as the coagulation inhibitor antithrombin III, which has a protein structure and has the ability to inhibit two or more coagulation factors, fibrinolysis and the complement system. As pregnancy progresses, there is a gradual decrease in the activity of antithrombin III. In pregnant women, starting from early pregnancy, the level of D-dimer in the blood gradually increases. By the end of pregnancy, its values ​​can be 3-4 times higher than the initial level. Lupus anticoagulant should not be produced normally in a pregnant woman. Pregnant women may experience minor changes in the general blood count (No. 5)*. Indicators such as hemoglobin and hematocrit may decrease in the second half of pregnancy, and leukocytes may increase (No. 119)*. Changes in biochemical parameters
During pregnancy, a decrease in the total protein concentration in the blood plasma is due to both partial dilution, as a result of fluid retention in the body, and a decrease in the concentration of albumin (No. 10)*. The decrease in albumin is due to its increased consumption on biosynthetic processes. However, it is impossible to exclude the factor of increased vascular permeability and redistribution of fluid and protein in the intercellular space, and hemodynamic disturbances. Changes in the concentration of blood proteins are also detected on the proteinogram. In the first and second trimester of pregnancy, albumin decreases, which is associated with physiological hypervolemia. In the third trimester, an increase in the alpha-1-globulin fraction (No. 29)* and alpha-fetoprotein (No. 92)* is detected. Alpha-2-globulin fraction (No. 29)* can increase due to proteins associated with pregnancy (begin to increase from 8-12 weeks of pregnancy and reach a maximum in the third trimester). Beta globulins (No. 29)* increase due to an increase in transferrin concentration (No. 50)*. Also, in most cases there is a slight increase in the level of gamma globulins (No. 29)*.

Minor changes in C-reactive protein (No. 43)*, observed more often in early pregnancy, may be the body’s response to proliferation processes (increased cell division). Changes in circulating blood volume (CBV) and blood supply to the kidneys lead to changes in the nitrogen excretory function of the kidneys. There is a delay and accumulation of nitrogenous substances, while the amount of urea (No. 26)* decreases, especially in late pregnancy due to increased protein utilization (positive nitrogen balance).

Creatinine (No. 22)* decreases maximum in the 1st - 2nd trimester (its concentration can decrease by almost 1.5 times), which is associated with an increase in the volume of muscle mass of the uterus and fetus. The level of uric acid (No. 27)* is often reduced due to increased blood supply to the kidneys, but even minor renal dysfunction can lead to an increase in this indicator, and this is regarded as symptoms of toxemia.

Lipid metabolism changes significantly during pregnancy (profile No. 53)*. As oxidative processes intensify, there is an increased utilization of cholesterol in the adrenal glands and placenta. This leads to compensatory transient hypercholesterolemia, characterized by an increase in cholesterol and HDL levels. The HDL level remains virtually unchanged. An increase in estrogen levels leads to hypertriglyceridemia, which is facilitated by hypoproteinemia and functional cholestasis. At the same time, fat deposition in the mammary glands and subcutaneous fat increases; this process is also associated with an increase in the transition of carbohydrates to fats due to increased insulin production.

An indicator reflecting the level of endogenous insulin secretion is C-peptide (No. 148)*. Glucose values ​​(No. 16)* may change slightly without reaching the level of hyperglycemia. Since during pregnancy the glomerular filtration rate increases and the permeability of the epithelium of the renal tubules increases, glucosuria (physiological) may periodically be observed. Most often, glucosuria appears during pregnancy 27 - 36 weeks. Features of mineral metabolism in healthy pregnant women compared to non-pregnant women are the retention of sodium, potassium, chlorine (No. 39)*, phosphorus (No. 41)* salts in the body; it is changes in phosphorus levels in the body of a pregnant woman that are associated with an increase in alkaline phosphatase (No. 36) *. This is due to changes during pregnancy in bone tissue and changes in the liver. As you know, during pregnancy the need for calcium salts, which are necessary for the formation of the fetal skeleton, increases, and the mother may experience calcium deficiency (No. 37)*. Hypocalcemia in pregnant women can manifest itself in muscle cramps and spastic phenomena. Increased iron intake during pregnancy can lead to anemia. This condition is characterized by a decrease in iron (No. 48)*, ferritin (No. 51)*, vitamins: B12 (No. 117)*, folic acid (No. 118)*. Changes in the endocrine system

The pituitary gland, especially the anterior lobe, enlarges. Pituitary hormones ACTH (No. 100)*, prolactin (No. 61)* play a large role in changing the metabolic processes of the pregnant woman’s body. Therefore, these hormones may be elevated. The placenta also has hormonal activity. It produces progesterone (No. 63)*, free estriol (No. 134)*, b-hCG (No. 66)*, these hormones are similar in their action to somatotropin (No. 99)*. The thyroid gland also undergoes changes, it enlarges somewhat, and in the first half of pregnancy its hyperfunction is noted. There is an increase in free T4 (No. 55)*, with normal T4 levels (No. 54)*. There is also an increase in the function of the parathyroid glands with a relative increase in parathyroid hormone (No. 102)*. The production of FSH (No. 59)* decreases during pregnancy.

Hematocrit norms in different trimesters of pregnancy

A pregnant woman's body experiences significant changes. In addition to changing hormonal levels, a woman’s weight and the location of internal organs change. At the same time, the volume of circulating blood increases. The norm for a woman in normal condition is considered to be from 40% to 44-45%. During pregnancy, the hematocrit decreases:

• I trimester. Plasma increases by about 15%. The hematocrit number reaches values ​​in the range of 33-36%.
• II trimester. Blood volume increases rapidly. In this case, the hematocrit should not be lower than 31%. If this happens, then the woman has developed anemia.
• III trimester. In the last 3 months of gestation, the fetus gains body weight at an accelerated pace. To do this, it requires a larger amount of circulating blood. The hematocrit norm does not exceed 32-34%.

Consequences of lowering the indicator for the expectant mother and fetus

Often during gestation, the hematocrit number decreases. If the level of the indicator reaches critically low values, the body of the expectant mother begins to undergo pathological changes:

• the load on internal organs (heart muscle, kidneys and liver) increases;
• disruption of brain function;
• the amount of fluid in the body increases, while a lot of energy is spent on its removal;
• cells and tissues do not receive enough oxygen and important nutrients;
• iron deficiency anemia develops.

Along with this, the woman begins to feel severe weakness and fatigue.
Anemia may develop when there are extremely few red blood cells in the blood. The condition can provoke the development of bleeding in a woman. A low hematocrit is dangerous not only for the mother, but also for the life of the child. The baby does not receive enough oxygen, which it needs for proper growth, resulting in severe hypoxia. It is important to undergo medical examinations prescribed by your doctor in a timely manner to prevent the development of complications.

Causes of low hematocrit

During pregnancy, doctors often diagnose patients with a low hematocrit level. This is due to a lack of iron in the body (anemia).

Other reasons affecting the decrease in hematocrit number:

• diseases of the digestive tract;
• infections;
• unbalanced diet;
• pathological processes in the kidneys or liver.

What is hematocrit, why is it important to measure this indicator?

Hematocrit is a measure of the content of red blood cells (erythrocytes) in human blood. When donating blood for general analysis, the hematocrit number is not determined. This manipulation is carried out only as prescribed by a specialist. To do this, a laboratory technician takes blood from a vein, artery, or finger and places it in a special tube.

The test container is made of glass, and 100 marks are drawn on its surface. The tube with blood is placed in a centrifuge for 1.5–2 hours. During this time, the blood cells settle, and the laboratory assistant determines the percentage of plasma and red blood cells.

Before taking tests to determine hematocrit, it is necessary to carry out preparatory measures. To make the indicator more accurate, before donating blood you cannot:

• eat fatty foods (a pregnant woman is allowed to eat a light breakfast);
• do any physical work;
• be nervous and worried;
• drink alcohol and smoke.