Biochemical indicators of maternal iron in the third trimester of pregnancy and their relation with maternal anthropometry and neonatal weight

Abstract

Objectives: To evaluate seric iron, transferrin iron binding capacity and its saturation index in a group of pregnant women in Antioquia, northwestern Colombia, and to associate these indicators with maternal anthropometry and neonatal weight.

Methodology: This was a descriptive, cross sectional study of 16 women in the third trimester of pregnancy. Seric transferrin was determined by nephelometry, seric iron and transferrin iron binding capacity were measured by photocolorimetry; the saturation index of transferring was calculated by a standard chemical formula. Maternal anthropometry was based on the body mass index (BMI) and total body weight gain; neonatal weight was measured in the delivery room, with a high precision equipment.

Results: Seric iron concentration and transferring saturation index indicated iron–deficient erythropoiesis and anemia, even though the average hemoglobin concentration was above 11.3 g/dL. Hemoglobin concentration was lower in mothers with low BMI, and neonatal weight correlated positively with maternal hemoglobin.

Conclusion: Seric iron and transferrin saturation index may be biomarkers of the iron status with earlier response than hemoglobin to the deficiency of this mineral. Maternal iron should be monitorized and iron needs satisfied in order to improve the weight of newborns.