Anemia in pregnancy

Anemia during pregnancy is a pathological condition characterized by a decrease in the number of red blood cells and/or hemoglobin per unit volume of blood. The frequency of this pregnancy complication is observed, according to various sources, in 18-75% (on average 56%) of women.

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Iron deficiency anemia in pregnant women

Iron deficiency anemia during pregnancy is a disease in which there is a decrease in the level of iron in the blood serum, bone marrow and storage organs, as a result of which the formation of hemoglobin is disrupted, and subsequently of red blood cells, hypochromic anemia and trophic disorders in tissues occur.

This complication has a negative impact on the course of pregnancy, childbirth and the condition of the fetus. Low iron levels in the body lead to a weakening of the immune system (phagocytosis is inhibited, the response of lymphocytes to stimulation by antigens is weakened, and the formation of antibodies, proteins, and the receptor apparatus of cells, which includes iron, is limited).

It should be taken into account that in the first trimester of pregnancy, the need for iron decreases due to the cessation of its loss during menstruation. During this period, iron losses through the digestive tract, skin and urine (basal losses) amount to 0.8 mg/day. From the second trimester until the end of pregnancy, the need for iron increases to 4-6 mg, and in the last 6-8 weeks it reaches 10 mg. This is primarily due to the increase in oxygen consumption by the mother and fetus, which is accompanied by an increase in the volume of circulating plasma (about 50%) and the mass of erythrocytes (about 35%). To ensure these processes, the mother's body requires approximately 450 mg of iron. Subsequently, the need for iron is determined by the body weight of the fetus. Thus, with a body weight of more than 3 kg, the fetus contains 270 mg, and the placenta - 90 mg of iron. During childbirth, a woman loses 150 mg of iron with blood.

Under the most optimal nutritional conditions (iron intake in bioavailable form - veal, poultry, fish) and consumption of sufficient ascorbic acid, iron absorption does not exceed 3-4 mg/day, which is less than physiological needs during pregnancy and lactation.

Causes of Iron Deficiency Anemia During Pregnancy

The reasons that can cause anemic syndrome are varied and can be conditionally divided into two groups:

1. Existing before the current pregnancy. These are limited iron reserves in the body before pregnancy, which can be caused by such conditions as insufficient or inadequate nutrition, hyperpolymenorrhea, an interval between births of less than 2 years, a history of four or more births, hemorrhagic diathesis, diseases that are accompanied by impaired iron absorption (atrophic gastritis, condition after gastrectomy or subtotal resection of the stomach, condition after resection of a significant part of the small intestine, malabsorption syndrome, chronic enteritis, intestinal amyloidosis, etc.), constant use of antacids, iron redistribution diseases (systemic connective tissue diseases, purulent-septic conditions, chronic infections, tuberculosis, malignant tumors), parasitic and helminthic invasions, liver pathology, impaired deposition and transport of iron due to impaired transferrin synthesis (chronic hepatitis, severe gestosis).
2. Those that arose during the current pregnancy and exist in pure form or superimposed on the first group of causes of anemia. These are multiple pregnancies, bleeding during pregnancy (bleeding from the uterus, nose, digestive tract, hematuria, etc.).

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Symptoms of Iron Deficiency Anemia During Pregnancy

In case of iron deficiency in the body, anemia is preceded by a long period of latent iron deficiency with clear signs of a decrease in its reserves. With a significant decrease in the hemoglobin level, symptoms caused by hemic hypoxia (anemic hypoxia) and signs of tissue iron deficiency (sideropenic syndrome) come to the fore.

Anemic hypoxia (actually anemic syndrome) is manifested by general weakness, dizziness, pain in the heart area, pale skin and visible mucous membranes, tachycardia, shortness of breath during physical exertion, irritability, nervousness, decreased memory and attention, and loss of appetite.

Iron deficiency is characterized by sideropenic symptoms: fatigue, memory impairment, muscular system damage, taste perversion, hair loss and brittleness, brittle nails. Patients often experience dry and cracked skin on their hands and feet, angular stomatitis, cracks in the corners of the mouth, glossitis, as well as gastrointestinal tract damage - hypo- or antacidity.

Diagnosis of iron deficiency anemia during pregnancy

When making a diagnosis, it is necessary to take into account the gestational age. Normally, hemoglobin and hematocrit decrease in the first trimester of pregnancy, reach minimum values in the second and then gradually increase in the third trimester. Therefore, in the first and third trimesters, anemia can be diagnosed at a hemoglobin level below 110 g/l, and in the second trimester - below 105 g/l.

It should be taken into account that a decrease in hemoglobin concentration is not evidence of iron deficiency, so additional testing is necessary, which, depending on the laboratory’s capabilities, should include two to ten of the following tests:

The main laboratory criteria of iron deficiency anemia: erythrocyte microcytosis (combined with aniso- and poikilocytosis), erythrocyte hypochromia (color index <0.86), decreased mean corpuscular hemoglobin content (<27 pg), decreased mean corpuscular hemoglobin concentration (<33%), decreased mean corpuscular volume (<80 μm3 ⁾; decreased serum iron (<12.5 μmol/l), decreased serum ferritin concentration (<15 μg/l), increased total iron-binding capacity of serum (>85 μmol/l), decreased transferrin saturation with iron (<15%), increased protoporphyrin content in erythrocytes (<90 μmol/l).

It is mandatory to determine the color index and identify microcytosis in a blood smear (the simplest and most accessible methods). It is desirable to determine the concentration of serum iron.

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Treatment of iron deficiency anemia during pregnancy

Treatment of iron deficiency anemia has its own characteristics and is determined by the degree of its severity and the presence of concomitant extragenital diseases and complications during pregnancy.

When determining treatment tactics, it is necessary:

• eliminate the causes of iron deficiency (gastric, intestinal, nasal bleeding, as well as from the birth canal, hematuria, blood clotting disorders, etc.);
• avoid consuming foods that reduce the absorption of iron in the patient's body (cereals, bran, soy, corn, water with a high content of carbonates, bicarbonates, phosphates, tetracyclines, almagel, calcium, magnesium, aluminum salts, red wine, tea, milk, coffee);
• recommend oral administration of iron preparations (except for cases in which oral administration of the preparation is contraindicated). Preventive administration of iron preparations (60 mg) is necessary for all pregnant women starting from the second trimester of pregnancy and for 3 months after delivery.

The therapeutic daily dose of alimentary iron when taken orally should be 2 mg per 1 kg of body weight or 100-300 mg/day.

When choosing a specific iron-containing drug, it should be taken into account that among ionic iron compounds, it is preferable to use drugs containing divalent iron, since its bioavailability is significantly higher than trivalent iron. It is advisable to prescribe drugs with a high iron content (1-2 tablets correspond to the daily requirement) and drugs with its slow release (retard forms), which allows maintaining a sufficient concentration of iron in the blood serum and reducing gastrointestinal side effects.

It is necessary to use combination drugs, the additional components of which prevent the oxidation of divalent iron into trivalent iron (ascorbic, succinic, oxalate acids), promote the absorption of iron in the intestine (amino acids, polypeptides, fructose), prevent the irritating effect of iron ions on the mucous membrane of the digestive tract (mucoproteosis), weaken the antioxidant effect of divalent iron (ascorbic acid and other antioxidants), maintain the brush border of the mucous membrane of the small intestine in an active state (folic acid).

Contraindications to taking iron preparations orally are iron intolerance (constant nausea, vomiting, diarrhea), condition after resection of the small intestine, enteritis, malabsorption syndrome, exacerbation of peptic ulcer disease, nonspecific ulcerative colitis or Crohn's disease.

If there are contraindications to oral administration of iron preparations, parenteral administration of preparations containing trivalent iron is prescribed. In case of parenteral administration, the daily dose of iron should not exceed 100 mg.

Due to the risk of liver hemosiderosis, treatment with parenteral iron preparations should be carried out under the control of serum iron levels.

Side effects of iron supplements

When taken orally, they are associated mainly with local irritant effects: nausea, pain in the epigastric region, diarrhea, constipation, minor allergic reactions (skin rash). When administered parenterally, local tissue irritation is possible, as well as pain in the heart region, arterial hypotension, arthralgia, enlarged lymph nodes, fever, headache, dizziness, infiltration of the injection site, anaphylactoid reactions, anaphylactic shock.

There is evidence indicating a more pronounced effect of ferrotherapy when combined with the intake of folic acid, human recombinant erythropoietin, and multivitamin preparations containing minerals.

If severe symptomatic anemia occurs in late pregnancy (more than 37 weeks), it is necessary to decide on the transfusion of red blood cells or washed red blood cells.

Prevention of iron deficiency anemia is indicated for pregnant women who are at risk. It is based on rational nutrition and the use of iron preparations. Nutrition should be complete, contain sufficient amounts of iron and protein. The main source of iron for a pregnant woman is meat. Iron in the heme form is absorbed better and from plant foods is worse,

To improve iron absorption, include fruits, berries, green vegetables, juices and fruit drinks, and honey (dark varieties) in your diet.

The consumption of meat and products that promote better absorption of iron should be separated in time from tea, coffee, canned foods, cereals, milk and fermented milk products containing compounds that inhibit iron absorption.

For anemia, decoctions or infusions of rose hips, elderberries, black currants, strawberry leaves and nettles are recommended.

Prevention of iron deficiency anemia during pregnancy

Prevention of iron deficiency anemia also involves continuous intake of iron preparations (1-2 tablets per day) during the third trimester of pregnancy. Iron preparations can be used in courses of 2-3 weeks with breaks of 2-3 weeks, a total of 3-5 courses during the entire pregnancy. The daily dose for the prevention of anemia is about 50-60 mg of divalent iron. Improvement of erythropoiesis is facilitated by the inclusion of ascorbic and folic acid, vitamin E, B vitamins, microelements (copper, manganese) in the therapy.

B12-deficiency anemia in pregnancy

Anemia due to vitamin B12 deficiency _is characterized by the appearance of megaloblasts in the bone marrow, intramedullary destruction of erythrocytes, a decrease in the number of erythrocytes (to a lesser extent - hemoglobin), thrombocytopenia, leukopenia and neutropenia.

_{The human body can absorb up to 6-9 mcg of vitamin B 12} per day, the normal content of which is 2-5 mg. The main organ that contains this vitamin is the liver. Since not all vitamin B ₁₂ is absorbed from food, it is necessary to receive 3-7 mcg of the vitamin per day in the form of a preparation.

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Causes of B12 Deficiency Anemia During Pregnancy

_{Vitamin B12} deficiency occurs due to insufficient synthesis of Castle's intrinsic factor, which is necessary for the absorption of the vitamin (observed after resection or removal of the stomach, autoimmune gastritis), impaired absorption processes in the ileal part of the intestine (nonspecific ulcerative colitis, pancreatitis, Crohn's disease, dysbacteriosis, i.e. the development of bacteria in the cecum, helminthiasis (broad tapeworm), conditions after resection of the ileal part of the intestine, vitamin B12 deficiency _in the diet (absence of animal products), chronic alcoholism, and the use of certain medications.

The pathogenesis of B12-deficiency anemia during pregnancy involves changes in hematopoiesis and epithelial cells associated with impaired thymidine formation and cell division (cells increase in size, megaloblastic hematopoiesis).

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Symptoms of B12 Deficiency Anemia During Pregnancy

With a deficiency of vitamin B _^12, changes occur in the hematopoietic tissue, digestive and nervous systems.

_{Vitamin B12} deficiency manifests itself through signs of anemic hypoxia (rapid fatigue, general weakness, palpitations, etc.). In severe anemia, yellowing of the sclera and skin, and signs of glossitis are observed.

Occasionally, hepatosplenomegaly occurs and gastric secretion decreases.

A characteristic sign of _B12 -deficiency anemia is damage to the nervous system, the symptoms of which are paresthesia, sensory disturbances with pain, a feeling of cold, numbness in the extremities, crawling ants, often muscle weakness, dysfunction of the pelvic organs. Mental disorders, delirium, hallucinations are extremely rare, and in very severe cases - cachexia, areflexia, persistent paralysis of the lower extremities.

Diagnosis of B12-deficiency anemia during pregnancy

The diagnosis is based on the determination of the content of vitamin B ₁₂ (decreases below 100 pg/ml with the norm being 160-950 pg/l) against the background of the presence of hyperchromic macrophages, Jolly bodies in erythrocytes, an increase in the level of ferritin, a decrease in the concentration of haptoglobin, and an increase in LDH. The diagnostic criteria also include the presence of antibodies to the intrinsic factor or to parietal cells in the blood serum (diagnosed in 50% of cases).

If cytopenia with a high or normal color index is detected in a pregnant woman, a bone marrow puncture must be performed. The myelogram reveals signs of megaloblastic anemia.

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Treatment of B12-deficiency anemia during pregnancy

Treatment consists of administering cyanocobalamin 1000 mcg intramuscularly once a week for 5-6 weeks. In severe cases, the dose may be increased.

A lot of vitamin B ₁₂ is found in meat, eggs, cheese, milk, liver, kidneys, which should be taken into account when carrying out prevention.

In case of helminthic invasion, deworming is prescribed.

In all cases of vitamin B ₁₂ deficiency, its use leads to rapid and lasting remission.

Folic acid deficiency anemia in pregnancy

Anemia associated with folate deficiency is accompanied by the appearance of megaloblasts in the bone marrow, intramedullary destruction of erythrocytes, pancytopenia, macrodytosis and hyperchromia of erythrocytes.

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Causes of folate deficiency anemia during pregnancy

The cause of the development of folate deficiency anemia may be an increase in the need for folic acid during pregnancy by 2.5-3 times, that is, over 0.6-0.8 mg/day.

Risk factors for the development of folate deficiency anemia during pregnancy also include hemolysis of various origins, multiple pregnancy, long-term use of anticonvulsants, and a condition following resection of a significant portion of the small intestine.

Folic acid, together with vitamin B, is involved in the synthesis of pyridine, glutamic acid, purine and pyrimidine bases necessary for the formation of DNA.

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Symptoms of folate deficiency anemia during pregnancy

Folic acid deficiency is manifested by signs of anemic hypoxia (general weakness, dizziness, etc.) and symptoms similar to those in B, deficiency anemia. There are no signs of atrophic gastritis with achylia, funicular myelosis, hemorrhagic diathesis. Functional signs of CNS damage are expressed. Diagnostics. Folic acid deficiency is characterized by the appearance of macrocytosis in the peripheral blood, hyperchromic anemia with anisocytosis and a reduced number of reticulocytes, thrombocytopenia and leukopenia, in the bone marrow - the presence of megaloblasts. Folic acid deficiency is noted in the serum and especially in erythrocytes.

Treatment of folate deficiency anemia during pregnancy

Treatment is carried out with folic acid preparations at a dose of 1-5 mg/day for 4-6 weeks until remission occurs. Subsequently, if the cause is not eliminated, maintenance therapy with folic acid preparations at a dose of 1 mg/day is prescribed.

The dose of folic acid is increased to 3-5 mg/day during pregnancy, provided that anticonvulsants or other antifolic agents (sulfasalazine, triamterene, zidovudine, etc.) are taken on a regular basis.

Prevention of folate deficiency anemia during pregnancy

Additional intake of folic acid at a dose of 0.4 mg/day is recommended for all pregnant women, starting from the early stages. This reduces the incidence of folate deficiency and anemia and does not have an adverse effect on the course of pregnancy, childbirth, the condition of the fetus and newborn.

Taking folic acid by women in the preconception period and in the first trimester of pregnancy helps to reduce the frequency of congenital anomalies of the fetal CNS development by 3.5 times compared to the general population indicators. Taking folic acid, which begins after 7 weeks of pregnancy, does not affect the frequency of neural tube defects.

It is necessary to consume sufficient amounts of fruits and vegetables rich in folic acid (spinach, asparagus, lettuce, cabbage, including broccoli, potatoes, melon), in raw form, since most of the folates are lost during heat treatment.

Thalassemia in pregnancy

Thalassemia is a group of hereditary (autosomal dominant type) hemolytic anemias, characterized by a disruption in the synthesis of the alpha or beta chain of the hemoglobin molecule and, thus, a decrease in the synthesis of hemoglobin A. It is extremely rare in Ukraine.

In thalassemia, one of the globin chains is synthesized in small quantities. The chain that is formed in excess aggregates and is deposited in erythrokaryocytes.

Clinical picture and treatment

Patients have severe or mild hysterochromic anemia, with the iron content in the blood serum being normal or slightly elevated.

In mild forms of alpha-thalassemia, pregnancy proceeds without complications and treatment is not carried out. Severe forms require the administration of iron preparations per os, often - transfusions of erythrocyte mass.

A special form of alpha-thalassemia, which occurs when all four a-globin genes are mutated, almost always leads to the development of fetal hydrops and intrauterine death. This form is associated with a high incidence of preeclampsia.

If alpha-thalassemia is accompanied by splenomegaly, delivery is performed by cesarean section; in all other cases, through the natural birth canal.

Mild forms of beta-thalassemia, as a rule, do not interfere with pregnancy, which proceeds without complications. Treatment consists of prescribing folic acid, and occasionally there is a need for red blood cell transfusion. Patients with severe beta-thalassemia do not survive to reproductive age.

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Hemolytic anemia during pregnancy

Hemolytic anemias are caused by increased destruction of red blood cells, which is not compensated by activation of erythropoiesis. These include sickle cell anemia, which is a hereditary structural anomaly of the beta chain of the hemoglobin molecule, hereditary microspherocytosis as an anomaly of the structural protein of red blood cell membranes, that is, speckgrin, anemias caused by congenital enzymatic disorders, most often - deficiency of glucose-6-phosphate dehydrogenase of red blood cells,

The clinical picture of this type of anemia is formed by general symptoms of anemia (paleness, general weakness, shortness of breath, signs of myocardial dystrophy), hemolytic jaundice syndrome (jaundice, enlarged liver, spleen, dark urine and feces), signs of intravascular hemolysis (hemoglobinuria, black urine, thrombotic complications), as well as an increased tendency to form gallstones associated with high bilirubin content, in severe cases - hemolytic crises.

Pregnant women with hemolytic anemia in all cases require qualified management by a hematologist. Decisions regarding the possibility of carrying a pregnancy, the nature of treatment, the time and method of delivery are made by a hematologist. Prescription of iron preparations is contraindicated.

Aplastic anemia in pregnant women

Allastic anemias are a group of pathological conditions accompanied by pancytopenia and decreased hematopoiesis in the bone marrow.

The following mechanisms are distinguished in pathogenesis: a decrease in the number of stem cells or their internal defect, a disruption of the microenvironment leading to a change in the function of stem cells, immune suppression of the bone marrow, a defect or deficiency of growth factors, external influences that disrupt the normal function of the stem cell.

It is extremely rare in pregnant women. In most cases, the cause is unknown.

The leading place is given to anemic syndrome (anemic hypoxia syndrome), thrombocytopenia (bruising, bleeding, menorrhagia, petechial rash) and, as a consequence, neutropenia (purulent inflammatory diseases).

Diagnosis is made based on the results of a morphological examination of bone marrow puncture.

Pregnancy is contraindicated and subject to termination both in the early and late stages. In case of development of aplastic anemia after 22 weeks of pregnancy, early delivery is indicated.

Patients are at high risk for hemorrhagic and septic complications. Maternal mortality is high, and cases of antenatal fetal death are frequent.

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Classification of anemia in pregnancy

By etiology (WHO, 1992).

• Nutritional anemias
  • iron deficiency (D50);
  • B12-deficient (D51);
  • folate deficiency (D52);
  • other nutritional (D53).
• Hemolytic anemias:
  • due to enzymatic disorders (D55);
  • thalassemia (D56);
  • sickle-shaped disorders (D57);
  • other hereditary hemolytic anemias (058);
  • hereditary hemolytic anemia (D59).
• Aplastic anemia
  • hereditary red cell aplasia (erythroblastopenia) (D60);
  • other aplastic anemias (D61);
  • acute posthemorrhagic anemia (D62).
• Anemias in chronic diseases (D63):
  • neoplasms (D63.0);
  • other chronic diseases (D63.8).
• Other anemias (D64).

By severity

Degree of tension	Hemoglobin concentration, g/l	Hematocrit, %
Easy	109-90	37-31
Average	89-70	30-24
Heavy	69-40	23-13
Extremely difficult	<40	<13

In most cases, pregnant women develop iron deficiency anemia (90%), and in half of the cases, a combined iron and folate deficiency genesis is observed.

Other types of anemia in pregnant women are extremely rare.

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Adverse Effects of Anemia During Pregnancy

The prevailing view among specialists is that anemia of any nature, especially severe and/or long-term, has an adverse effect on the health of the mother and fetus. According to WHO (2001), anemia and iron deficiency in pregnant women are associated with increased maternal and perinatal mortality and an increase in the frequency of premature births. Anemia can be the cause of low birth weight babies, which causes an increase in morbidity and mortality in newborns, prolongation of labor and an increase in the frequency of surgical interventions during labor.

The results of a meta-analysis of data on the effect of anemia on the course of pregnancy and its outcome indicate that adverse effects depend not only on anemia, but also on many other factors that are difficult to take into account and which, in turn, may be caused by anemia.

It is generally accepted that severe anemia (Hb < 70 g/l) has a negative impact on the condition of the mother and fetus, leading to dysfunction of the nervous, cardiovascular, immune and other body systems, an increase in the incidence of premature births, postpartum infectious and inflammatory diseases, intrauterine growth retardation, neonatal asphyxia and birth trauma.

The presented evidence-based medicine data determine the need for effective prevention and treatment of this pregnancy complication.

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