In our study population, about 85% of the women were 20–29 y-old, 72% had normal BMI (range 18.5–24.9 kg/m2), 36.1% did not have anaemia (Hb ≥ 110 g/l), 35.4% were primiparous, and 15.1% had no formal education (Table 1). This evidence concerns the gene GSTM1 and anemia (phenotype).