Objective: We studied the association between anemia in pregnancy and characteristics related to nutrition and infections.

Design: Cross-sectional study.

Setting: Four antenatal clinics in rural northern Tanzania.

Subjects/methods: A total of 2547 women were screened for hemoglobin (Hb) and malaria plasmodia in capillary blood and for infections in urine. According to their Hb, they were assigned to one of five groups and selected accordingly, Hb<70 g/l (n=10), Hb=70-89 g/l (n=61), Hb=90-109 g/l (n=86), Hb=110-149 g/l (n=105) and Hb> or =150 g/l (n=50). The 312 selected subjects had venous blood drawn, were interviewed, and their arm circumference was measured. The sera were analyzed for ferritin, iron, total iron binding capacity (TIBC), cobalamin, folate, vitamin A, C-reactive protein (CRP), and lactate dehydrogenase (LD). Transferrin saturation (TFsat) was calculated. Urine was examined by dipsticks for nitrite.

Main outcome measures: Unadjusted and adjusted odds ratio (OR and AOR) of anemia with Hb<90 g/l.

Results: Anemia (Hb<90 g/l) was associated with iron deficiency (low s-ferritin; AOR 3.4). The association with vitamin deficiencies were significant in unadjusted analysis (low s-folate; OR 3.1, low s-vitamin A; OR 2.6). Anemia was also associated with markers of infections (elevated s-CRP; AOR 3.5, urine nitrite positive; AOR 2.4) and hemolysis (elevated s-LD; AOR 10.1). A malaria positive blood slide was associated with anemia in unadjusted analysis (OR 2.7). An arm circumference less than 25 cm was associated with anemia (AOR 4.0). The associations with less severe anemia (Hb 90-109 g/l) were similar, but weaker.

Conclusions: Anemia in pregnancy was associated with markers of infections and nutritional deficiencies. This should be taken into account in the management of anemia at antenatal clinics.

Sponsorship: The study was supported by the Norwegian Research Council (NFR) and the Centre for International Health, University of Bergen.