The role of haematological indices in predicting early iron deficiency among pregnant women in an urban area of Sri Lanka.

Background: Early detection and treatment of iron deficiency during pregnancy is crucial for optimum pregnancy outcomes. Anaemia is a late indictor of iron deficiency measured as Hb < 11 g/dL, and is widely used as a proxy for iron deficiency. We aimed to evaluate the role of red cell indices as a screening tool for early detection of iron deficiency among pregnant women in an urban area of Sri Lanka.

Method: A cross-sectional study was conducted among 110 apparently healthy pregnant women ≤12 weeks of gestation attending antenatal clinics in Colombo, Sri Lanka. Women already on nutritional supplements were excluded. Full blood count, serum ferritin (SF) and high sensitive C-reactive protein (hs-CRP) assessments were performed. The women with evidence of inflammation as indicated by hs-CRP > 10 mg/L were excluded (N = 20) from data analysis. Anaemia (Hb < 11 g/dL) and iron deficiency (SF < 30 μg/L) were defined according to WHO guidelines. Receiver operating characteristics curves were used to derive red blood cell indices that showed the optimal cut-offs in detecting early iron deficiency.

Results: Of the 90 women, 63 (70.0%) were iron deficient (SF < 30 μg/L), out of whom 10 (15.9%) were identified as having iron deficiency anaemia (Hb < 11 g/dL). A high sensitivity (> 70%) in the prediction of iron deficiency was obtained for the optimal cut-off values of Hb < 12.2 g/dL, MCV < 83.2 fl, MCH < 26.9 pg and MCHC 33.2 g/dL while maintaining a specificity > 40%.

Conclusion: Iron deficiency can be predicted in early stages using Hb and red cell indices, which is much less expensive. This could be a useful method in areas with limited resources and a high prevalence of iron deficiency.