Evaluation of iron balance in healthy pregnant women and their newborns

Abstract

Aim of the study: The aim of this study was to evaluate the iron status markers in normal healthy pregnancy, as well as the influence of maternal diet on iron concentration in their newborns. Material and methods: A longitudinal prospective study was conducted in a sample of 69 healthy, non-smoking pregnant women under prenatal care of The Institute of Mother and Child. Blood samples were collected in the first, second and third trimesters and from the umbilical vein. Concentrations of ferritin and transferrin were assessed using turbidimetric technique, the concentration of iron - with ferrozine colorimetric method. Pentra 120 analyzer was used to define hematological parameters. Maternal diet was assessed by means of a weekly questionnaire, processed with computer software Dietetyk 2. Results: Hematological parameters in the analyzed blood were normal. The average hematocrit values in the first trimester of pregnancy was 36.7%, in the second - 34.92%, in the third - 35.95%. The concentration of hemoglobin was 27.82g/dl, 28.55g/dl, 27.27g/dl in the respective trimesters of pregnancy. In the umbilical blood it was 25.84g/dl (5.2% less than in the maternal blood). The number of erythrocytes was the highest in the first (4.16mln/mm3), and the lowest in the second trimester (3.92mln/mm3). The average concentration of iron was the highest in the first trimester - 99.61μg/dl. In the second and third trimester it decreased by 25% and 2% respectively. The concentration was 76.34% higher in the umbilical blood than in maternal blood at the time of labor. The concentration of ferritin in the first trimester was 43.96μg/l, in the second and the third trimester it was lower by 46% and 29% respectively. It was 126.4μg/l in the umbilical blood (fourfold higher than in maternal blood). The concentration of transferrin was 321.01mg/dl in the first trimester and it increased in consecutive trimesters by 36.14% and 5.12%; it was 219.92mg/dl in the umbilical blood - 48% of the concentration of transferrin in the maternal blood at the time of labor. The analysis of an average daily food ration revealed that the supply of iron was 80% of the recommended dose in the first half and only 41% of the recommended dose in the second half of the pregnancy. Fat consumption was 99% and 95% of the recommended dose, respectively. There was a 30%-decrease in the protein and carbohydrates consumption in comparison with the recommended dose in the second half of the pregnancy. Conclusions: In spite of normal hematological parameters, we observed insufficient supply of iron in the diet of pregnant women, which was demonstrated by a decreased level of ferritin. It should be reason enough to issue dietary recommendations and guidelines for pregnant women in each stage of pregnancy.