Seven of these 12 studies used the same definitions of iron deficiency (serum ferritin <30 ng/mL with CRP< = 8.2 ng/mL or serum ferritin <70 ng/mL with CRP>8.2 ng/mL), and pooled analysis showed an overall decreased odds for peripheral parasitemia in pregnancy (ORpooled 0.35, 95% CI 0.24–0.51; I2 59.2%, five studies, figure 3) associated with iron deficiency, but this was not significant for placental malaria (ORpooled 0.34, 95% CI 0.11–1.10; I2 75·8%, two studies, figure 4). This evidence concerns the gene CRP and parasitic infectious disease.