Anemia during pregnancy is a decrease in hemoglobin levels that occurred during gestation and is pathogenetically associated with it. It is manifested by weakness, fatigue, dizziness, perversion of taste and olfactory preferences, cardiac pain, muscle weakness, paresthesia, mucosal lesions, skin changes, nails, hair. It is diagnosed using a general clinical blood test and a laboratory study of iron metabolism. For treatment, iron-containing drugs, folic acid, cyanocobalamin are used, according to indications, complex antihypoxic therapy is carried out.
O99.0 Anemia complicating pregnancy, childbirth and the postpartum period
The existence of physiological prerequisites for the occurrence of gestational anemia (hydremia) makes this disease one of the most common types of pathology during pregnancy. Manifest forms of the disease with clinically pronounced symptoms in economically developed countries occur in 16-21% of patients, in developing countries their prevalence reaches 80%. At the same time, latent iron deficiency, taking into account the usefulness of the diet, is observed in 50-100% of women by the end of pregnancy. The predominant form of anemia of the gestational period is iron deficiency, diagnosed in 75-95% of cases. The urgency of timely detection of pathology is associated with a high probability of complicated pregnancy and the occurrence of hypoxic conditions against the background of a physiological increase in oxygen demand by 15-33%.
The insufficient content of hemoglobin and erythrocytes in the blood of a pregnant woman is due to both factors directly related to gestation and previous diseases. According to the observations of specialists in the field of obstetrics, in most patients gestational hydremia has such easily explicable physiological causes as:
- Increased need for iron. Starting from the second trimester of pregnancy, more iron is required for adequate maintenance of the fetoplacental complex. This trace element is rapidly consumed by the growing fetus, enters the placenta, and is used to increase the total number of red blood cells circulating in a woman’s blood. By the beginning of the third trimester, the daily need of a pregnant woman for iron is at least 4-6 mg, and at 32-34 weeks it requires at least 10 mg / day.
- Physiological hemodilution. During pregnancy, the volume of circulating plasma increases by 40-50%, and the volume of erythrocyte mass only by 20-35%. This is due to the increased need of the body for iron and plastic substances, with insufficient intake of which the rates of erythropoiesis do not correspond to the rate of increase in CBV. According to WHO recommendations, the permissible hemoglobin level in pregnant women has been reduced to 110.0 g / l, and hematocrit — up to 33%.
The factor aggravating anemia in the postpartum period is the physiological loss of up to 150 ml of blood during childbirth, in every 2.0-2.5 ml of which contains up to 1 mg of iron. Experts also identify a number of pathological causes that cause the disease. A decrease in the volume of erythrocytes (microcytic variant of anemia) with a corresponding drop in hemoglobin levels is observed in poisoning with industrial poisons (for example, lead), many chronic diseases (rheumatism, diabetes mellitus, peptic ulcer, gastritis, chronic infectious processes), sideroblastic anemia, thalassemia. This condition also occurs with iron deficiency due to the insufficiency of meat in the diet and the consumption of products containing non-heme forms of trace elements (plant foods, milk and dairy products).
Normocytic anemia with a reduced content of normal erythrocytes is more often observed in blood loss due to placental pathology, chronic renal failure, hypothyroidism, hypopituitarism, autoimmune hemolytic form of the disease, inhibition of erythropoiesis in the bone marrow. The macrocytic type of anemia with an increase in the volume of red blood cells is characteristic of folic acid and vitamin B12 deficiency, acute myelodysplastic syndrome, hepatic pathology (hepatitis, cirrhosis), alcohol dependence, reticulocytosis. Additional risk factors are the low material standard of living of a pregnant woman, frequent childbirth, multiple pregnancies, long breastfeeding with a short interpartum interval, complicated course of this pregnancy (pronounced early toxicosis with repeated vomiting, gestosis).
The mechanism of anemia formation during pregnancy is usually associated with a violation of the balance between the intake of iron into the body, especially in combination with a deficiency of protein, folic acid, vitamin B12, and their high consumption for plastic purposes. An additional link in the pathogenesis is the inhibition of erythropoiesis due to an increase in the concentration of estradiol and the accumulation of metabolites that have a toxic effect on the bone marrow. The situation is aggravated by immunological changes associated with the constant stimulation of the mother’s body by fetal antigens, which increases anti-tissue sensitization. The results of pathophysiological processes are tissue, hemic and circulatory hypoxia with metabolic disorders and further accumulation of harmful metabolic products.
The optimal criteria for the systematization of forms of anemia in pregnant women are the concentration of hemoglobin in the blood and the element or substance whose deficiency led to the onset of the disease. This approach to classification allows you to more accurately predict possible complications and select a pregnancy management scheme. Modern obstetricians and gynecologists distinguish the following forms of gestational anemia:
- According to the severity: according to the WHO classification, taking into account the level of hemoglobin, the disease is mild (90-109 g / l), moderate (70-89 g / l), severe (less than 70 g / l).
- By type of deficiency: iron deficiency anemia is the most common (it occupies about 95% in the structure of morbidity), folic deficiency and B12-deficiency forms of the disease are less common.
Symptoms of anemia during pregnancy
The mild degree usually proceeds latently. With a decrease in the concentration of iron less than 90 g / l, signs of hemic hypoxia (actually anemic syndrome) and iron deficiency in tissues (sideropenic syndrome) become noticeable. The possible development of oxygen starvation is indicated by general weakness, dizziness, tinnitus, discomfort and pain in the precardial region, complaints of palpitations, shortness of breath during physical exertion. The mucous membranes and skin look pale. A woman becomes irritable, nervous, inattentive, her memory decreases, her appetite worsens.
Tissue iron deficiency is manifested by rapid fatigue, perverted taste (desire to eat plaster, chalk, clay, sand, minced meat, raw meat), thickening and fragility of nail plates, dryness and hair loss, muscle weakness, urinary incontinence due to weakening of the sphincter apparatus. In some patients, epithelial membranes are affected: cracks (“jams”) appear in the corners of the mouth, the oral mucosa becomes inflamed, complaints of itching, burning in the vulva area appear. With moderate and severe anemia, there is often a slight yellowness of the palms and nasolabial triangle associated with impaired carotene metabolism in iron deficiency, and “blue” of the sclera caused by dystrophic processes.
The probability of pregnancy complications directly depends on the severity of the disorders and the time of occurrence of the disease. Anemia that developed before conception is especially unfavorable. In such cases, primary placental insufficiency, hypoplasia of the fetal membranes, low location of the placenta and its presentation, early miscarriage, undeveloped pregnancy are possible. With the appearance of an anemic symptom complex in the II-III trimesters, the risk of gestosis, late miscarriages and premature birth, premature detachment of the normally located placenta increases.
With a severe course of the disease, myocardiodystrophy occurs, the contractility of the heart muscle worsens. As a consequence, hemic and tissue hypoxia are aggravated by circulatory, as a result, parenchymal organs of the pregnant woman suffer, decompensation of their function is observed. In childbirth, 10-15% of women in labor show weakness of labor forces, often there are abundant hypotonic bleeding. After childbirth, 10-12% of maternity hospitals and 35-37% of newborns develop various purulent-septic processes. 4 nursing mothers out of 10 have hypogalactia.
The presence of anemia in a pregnant woman poses an immediate threat to the child. Perinatal morbidity with such pathology can increase up to 100%, and mortality — up to 14-15%. Fetoplacental insufficiency causes fetal hypoxia in 63% of cases, hypoxic brain injury in 40%, and developmental delay in 32%. Almost a third of newborns are born in asphyxia. Deficiency of vitamin B12, folic acid causes abnormalities in the development of the spine and nervous system (spina bifida, etc.). In children whose mothers suffered from severe or severe anemia during pregnancy, the function of external respiration is worse established. In the postnatal period, they are more likely to lag behind in height and body weight, and are more prone to the occurrence of infectious diseases.
The key tasks of the diagnostic search for suspected anemia during pregnancy are considered to be the assessment of the severity of the disorder and the timely detection of complications. Since anemia is iron-deficient in most cases, laboratory methods for determining the level of iron and hemoglobin are the most informative for diagnosis:
A general blood test. The hemoglobin content is less than 110 g/l. The color index has been reduced to 0.85. The number of red blood cells is below 3.5×1012 cells/l. There are signs of microcytosis (reduction of the diameter of red blood cells less than 6.5 microns). In the morphological picture of erythrocytes, poikilocytosis and anisocytosis are possible.
Study of iron metabolism. The serum iron level is less than 12 mmol/l. The total iron-binding capacity of the serum has been increased to 85 mmol/l or more. The concentration of ferritin (less than 15 mcg/l) and iron saturation of transferrin (less than 16%) were reduced. The latent iron-binding capacity of blood has been increased.
To exclude B12-deficient and folate-deficient variants of anemia that occurred during pregnancy, the serum level of cyanocobalamin and folic acid is determined. Taking into account possible complications from the fetus, it is recommended to assess its condition in dynamics with fetometry, cardiotocography, phonocardiography. Differential diagnosis is carried out between different forms of the disease, hemoglobinopathies, anemia syndrome caused by pregnancy complications, and extragenital pathology.
Treatment of anemia during pregnancy
The main objectives of therapy in pregnant women with reduced hemoglobin are correction of iron deficiency, elimination of hypoxia, stabilization of hemodynamics and metabolism. With moderate and severe anemia, special attention is paid to supporting the adequate functioning of the fetoplacental complex. The treatment regimen includes medications that allow:
- Restore the hemoglobin content. In iron deficiency anemia, oral administration of optimally high doses of iron in a divalent form convenient for assimilation is recommended. Preferably, the use of depot preparations with a slow release of the element. Parenteral correction of anemia is carried out with intolerance to divalent iron taken orally, violation of its absorption by the gastrointestinal mucosa, aggravated peptic ulcer of the stomach or duodenum. Ascorbic acid is prescribed for more effective assimilation of the trace element. WHO experts recommend supplementing the intake of iron-containing drugs with folic acid, which prevents the development of folic deficiency anemia. Cyanocobalamin deficiency is the basis for parenteral administration of vitamin B12.
- Eliminate the effects of hypoxia. In order to ensure an adequate supply of oxygen and nutrients to the fetus, various elements of the uteroplacental blood flow system are comprehensively affected. To increase blood flow to the placenta, tocolytics are used to relax the uterine wall. Microcirculation can be improved with the help of angioprotectors and drugs that affect blood rheology. The appointment of membrane stabilizers, anticosidants, actovegin allows to increase the resistance of the fetus to hypoxia. Antihypoxic therapy is usually used for II-III degrees of anemia complicated by fetoplacental insufficiency. If necessary, drugs are used to correct metabolic acidosis and improve the cardiac activity of a pregnant woman.
Antianemic therapy is usually long-term, it allows you to completely normalize red blood counts only at 5-8 weeks of treatment. To increase the effectiveness of medicines, correction of the diet is mandatory. It is recommended to supplement the diet with foods rich in iron: beef, veal, lean ham, pork, beef, chicken liver, fish. It is necessary to reduce the amount of food that impairs the absorption of iron: cereals, bran, soy, corn, tea, coffee, milk, carbonate, bicarbonate, phosphate mineral water. With caution, almagel, tetracyclines, magnesium and calcium salts are prescribed, which can aggravate anemia.
Prognosis and prevention
Mild anemia, diagnosed in most pregnant women with reduced hemoglobin levels, does not pose a threat to the life of the mother and fetus. Timely correction of moderate and severe forms of the disease can significantly improve blood counts, prevent the development of complications. To prevent perinatal and maternal complications, a balanced diet, early administration of iron preparations to patients with a history of menorrhagia, a short interval between childbirth, prolonged lactation after previous childbirth, and multiple births are recommended. Women with anemia should be given increased attention during childbirth to quickly identify and correct possible labor disorders, postpartum bleeding.