GSTM1 and anemia: Likewise, a 1 g/dL increase in maternal preconception Hb was associated with an 11%–19% reduced risk of child anemia at 6 mo (0.89; 95% CI: 0.81–0.98), 12 mo (0.81; 95% CI: 0.74–0.89), and 24 mo (0.87; 95% CI: 0.79–0.95).