Efficacy of different doses of daily prophylactic iron supplementation in pregnant women: A systematic review and meta-analysis

Abstract

Introduction

Several randomized controlled trials (RCT) have been conducted in the past to determine the optimum dose of iron supplementation during pregnancy, but there is a lack of consensus among different guidelines regarding the appropriate dosage of iron for prophylaxis during pregnancy.

Methods

Relevant electronic databases were searched to identify publications describing RCTs comparing different daily dosages of iron supplementation during pregnancy. Meta-analysis for various efficacy and safety outcomes such as changes in blood hemoglobin, serum ferritin, serum iron, and serum transferrin saturation, as well as the frequency of adverse effects, was performed using random and fixed effect models suitably depending on the degree of heterogeneity. Two groups were compared: those receiving 60 mg elemental iron or less and those receiving more than 60 mg elemental iron per day. Additionally, the efficacy of those receiving 30 mg elemental iron per day and those receiving 60 mg elemental iron per day were also compared.

Results

A to total of 15 RCTs comprising 2726 participants were included in the meta-analysis. Change in blood hemoglobin levels was comparable between the ≤60 mg/day and >60 mg/day group (pooled estimate for mean difference, 0.01 [-0.11, 0.09], p = 0.86, I² = 96 %), but serum ferritin, iron level, and serum transferrin saturation change were higher in the >60 mg group (p < 0.0001, 0.008, and 0.02, respectively). Change in blood hemoglobin level was better in the 60 mg/day group compared to the 30 mg/day group (pooled estimate for mean difference, −0.11 [-0.21, 0.00], p = 0.04, I² = 90 %), as well as changes in serum ferritin and serum transferrin saturations (p = 0.004 and 0.0004, respectively).

Conclusion

Daily supplementation of 60 mg elemental iron is more efficacious than daily supplementation of 30 mg elemental iron for the prophylaxis of anemia in pregnant women (certainty of evidence-moderate), and daily supplementation of ≤60 mg elemental iron is equally efficacious compared to daily supplementation of >60 mg elemental iron for the prophylaxis of anemia in pregnant women (certainty of evidence-moderate).

Proespero registration no

CRD42023455485.