First Trimester Ferritin Is Superior over Soluble Transferrin Receptor and Hepcidin in Predicting Anemia in the Third Trimester: Result from a Cohort Study in Indonesia.

Introduction: Anemia in the third trimester has been identified as a risk factor for maternal and fetal morbidity that might lead to mortality. Due to its high cost, finding the best marker to predict anemia became more important to allow early prevention. Only one of ferritin, hepcidin, or soluble transferrin receptors can be picked for the prediction of anemia in the third trimester especially in low-resource setting.

Objective: This study aimed at defining the best marker among ferritin, hepcidin, or soluble transferrin receptor (sTfR) in the first trimester for prediction of anemia in the third trimester. Materials, Methods, and Setting. This diagnostic study was nested on the cohort study of vitamin D and its impact during pregnancy in Indonesia. Singleton pregnant mothers with normal fetus were recruited in the first trimester from four cities in West Java, Indonesia. The 304 pregnant women were screened for hepcidin, ferritin, and sTfR level in the sera. All biomarkers were measured by ELISA. Complete blood count (CBC) was done by impedance method measurement (Sysmex^R). Only subjects with complete data were included in analysis for diagnostic study to compare the three markers by finding the best receiver operating curve (RoC), likelihood ratio (LR), and risk estimate (RR).

Result: One-hundred and eighty-one pregnant women were eligible for analysis. The result of this study showed that the serum ferritin level in the first trimester was the best marker to predict anemia in the third trimester of pregnancy. Hepcidin and sTfR performed poorly. A new cutoff point of ferritin level ≤27.23 ng/ml yielded the best ROC with 67% area under curve (95% CI 60%-75%, p < 0.0001, Youden index J 0.28), specificity 86.29% (95% CI 79.0%-91.8%), LR (+) 3.07 (95% CI 1.8-5.3), and RR 2.48 (95% CI 1.67-3.68). These last figures were better than the previously used cutoff point of ferritin level below 30 ng/ml.

Conclusion: This study provided evidence that the serum ferritin level ≤27.23 ng/ml in the first trimester was the best marker to predict anemia in the third trimester. It was valuably useful for secondary screening of anemia in pregnancy, targeting subjects who may need rigorous approach for iron deficiency treatment in the prevention of anemia in pregnancy.