Abstract
Background. To estimate serial serum ferritin (SF) concentrations after 20 weeks of pregnancy in women at risk of having a preterm labor and to correlate them with the outcome of pregnancy. Methods. Venous blood samples were drawn serially at 26, 30 and 34 weeks of gestation in one hundred pregnant women who were at risk of having a preterm delivery. Samples were analyzed for hemoglobin (Hb), leukocyte count, hemotocrit serum iron (SI), total iron-binding capacity (TIBC), SF and transferrin saturation. Seventy-six subjects delivered at term and 24 subjects delivered before 37 weeks. The various parameters were compared between the term and the preterm groups. Results. Mean SF at different gestations in the term and the preterm group was not statistically different. Serial SF levels in subjects in the term group showed a declining trend with advancing gestation as seen in normal pregnancies. However, in the preterm group, a rising trend was observed. Further, SF levels of > 30 µg/dl at 26 weeks and > 40 µg/dl at 34 weeks were found to have a reasonable sensitivity and specificity for predicting preterm delivery. Conclusion. A SF concentration of > 40 µg/dl and a rise in SF concentration with increasing gestation should alert the clinician regarding the possibility of preterm delivery.