At delivery, gestational age higher than or equal to 37 weeks (P = 0.005) and more than four ANVs during the follow-up (P = 0.003) were associated with a higher Hb concentration, whereas malaria (P < 0.001) and low BMI (P = 0.012) were related to lower Hb levels. The gene discussed is GSTM1; the disease is malaria.