GSTM1 and anemia (phenotype): Bivariate analysis revealed no association of anemia (Hb < 110 g/L), parity, gravidity, gestational age, delivery method, preterm birth, birth weight, fetal sex, and gestation age for GBS screening with GBS colonization in late pregnancy (P > 0.05) while maternal age, gestational week of birth, and PROM were correlated with GBS colonization (P < 0.05).