Treatment of anemia using parenteral iron supplements
Authors: Breymann C. 
Published: July 2021

Background. Anemia occurs in 30 % of women of childbearing age worldwide. The main causes of iron deficiency and iron deficiency anemia (IDA) are the decrease in iron intake from food (vegetarian diet, unbalanced diet, anorexia, eating disorders), impaired iron absorption (celiac disease, malabsorption, concomitant digestive diseases, drug use), blood losses (menstrual bleeding, childbirth, surgery, gastrointestinal bleeding, blood donation), and the increased need for iron (children and adolescents, pregnancy and lactation, endurance exercise). In the 3rd trimester of pregnancy, the need for iron is almost 10 times higher than in the 1st trimester (7.5 vs. 0.8 mg per day).
Objective. To describe the treatment of anemia with parenteral iron supplements.
Materials and methods. Analysis of literature sources on this topic.
Results and discussion. Hemoglobin content <90 g/l increases the risk of miscarriage, low birth weight and gestational age, premature birth, preeclampsia and eclampsia. Low hematocrit (<29 %) is accompanied by an increase in the probability of growth retardation and fetal death. On the part of the pregnant woman, tolerance to physical activity worsens, the probability of heart failure increases (in severe anemia), the condition of the thyroid gland and wound healing deteriorates. Among children born to mothers with IDA, the probability of IDA is higher than among children born to mothers with normal hemoglobin levels (47.2 % vs. 6.5 %; Colomer I. et al., 1990). Childbirth deepens IDA due to blood loss. During vaginal childbirth or cesarean section 300-500 ml of blood is lost, in case of profuse bleeding – 500-1000 ml, and in case of profuse bleeding, uterus atony, and in case of the disseminated intravascular coagulation – 2-3 L or even more. Iron supplements are prescribed for the treatment of IDA. They can be divided into oral (iron salts, iron complexes, elemental iron) and parenteral. Pregnant women are recommended to take 60 mg of iron per day from the beginning of gestation (as early as possible) until the end of pregnancy, as well as during the first 3 months of lactation. Oral iron preparations have a number of side effects: constipation, diarrhea, heartburn, nausea, and epigastric pain. This causes unsatisfactory adherence: one in five women stops taking iron supplements. Polymaltose iron complex is tolerated slightly better than iron sulfate. In case of intolerance to oral drugs, intravenous iron may be prescribed. Its advantages include fast action and good efficiency. Drugs for intravenous administration are divided into iron preparations and iron complexes with carbohydrates (carboxymaltose, sucrose, dextran). The sucrose complex of iron allows to reach the maximum level of hemoglobin much faster than iron sulfate (6.6 against 9.4 weeks). According to German and French guidelines for the treatment of anemia in pregnant women, if the hemoglobin is reduced to <90 g/l, IDA should be treated with intravenous iron. In the recommendations of the Asia-Pacific region, the threshold value is 100 g/l.
Conclusions. 1. Insufficient iron levels before pregnancy and the increased need in iron during pregnancy justify the proactive assessment and correction of IDA in pregnant women. 2. In case of moderate anemia and early stages of pregnancy, normal iron levels can be restored before delivery with the help of oral medications. 3. Intravenous iron supplements normalize iron levels faster than oral ones.