Prevalence of Iron Deficiency Anaemia and the Diagnostic Utility of Soluble Transferrin Receptor and sTfR/Log Ferritin Index among Pregnant Women: A Cross-sectional Study

Abstract

Introduction: Anaemia is a significant global health concern, particularly among pregnant women. This condition, primarily caused by Iron Deficiency (ID), poses risks to both maternal and foetal health. However, interpreting iron status through biochemical tests faces challenges. While serum ferritin concentration is a specific indicator of ID, its accuracy can be compromised by factors like inflammation. Serum Soluble Transferrin Receptor (sTfR) has shown promise in accurately diagnosing anaemia, especially in pregnant women, as it remains unaffected by pregnancy-related changes. Nonetheless, studies on its efficiency have yielded mixed results. Aim: To study the prevalence of Iron Deficiency Anaemia (IDA) among pregnant women and also to evaluate the accuracy of sTfR levels and the sTfR/Log Ferritin Index as diagnostic markers in predicting IDA among pregnant women. Materials and Methods: This cross-sectional study was conducted at NEIGRIHMS, Shillong, Meghalaya, India, between April 2021 and November 2022. A total of 92 pregnant women in their first trimester were included in the study. An automated clinical chemistry analyser measured serum iron and high-sensitivity C-Reactive Protein (hsCRP). Serum ferritin and sTfR levels were assessed via chemiluminescence assay. Sensitivity and specificity of sTfR levels and the sTfR/Log Ferritin Index in predicting IDA were determined utilising the Receiver Operating Characteristic (ROC) curve. Results: Most participants, 38 individuals (41.3%), were aged 20 to 25 years. The prevalence of anaemia was observed in eight individuals, comprising 8.7%, with sTfR proving highly sensitive (87.5%) and specific (75%) for IDA at 25.24 nmol/L. Both sTfR (r=-0.360) and sTfR-ferritin Index (r=-0.344) had significant negative correlations with Haemoglobin (Hb) (p-value<0.001), while ferritin (r=0.156) didn’t correlate significantly with Hb (p-value=0.136). Notably, CRP didn’t affect sTfR levels, enhancing its reliability. Conclusion: sTfR levels and the sTfR-Ferritin index were significantly higher in pregnant women with IDA. They exhibited greater sensitivity and specificity compared to serum ferritin in detecting IDA.

Keywords

• biomarkers
• early gestation
• immunoassay
• peripheral blood smear