Effect size of MMS (vs. IFA) on LBW as modified by maternal anemia status (24): Among anemic women (Hb <110 g/L): RR 0.81 (95% CI: 0.74, 0.89)Among nonanemic women (Hb ≥110 g/L): RR 0.91 (95% CI: 0.85, 0.98). This evidence concerns the gene GSTM1 and anemia.