There was no effect of PO iron on average change in Hb value between admission and delivery (difference in means: 0.190, CI: -0.529, 0.909; p=0.597), on average change in mean corpuscular volume MCV between admission and delivery (difference in means: 1.335, CI: -0.301, 2.970; p=0.107), or on incidence of anemia at delivery (odds ratio: 0.438, CI: 0.084, 2.278; p=0.326; see Figures 2-3). Here, GSTM1 is linked to anemia (phenotype).