Background: Anemia is a global concern among pregnant women. In 2019, global prevalence in women aged 15-49 years was 29.9% and higher among pregnant (36.5%) than non-pregnant women (29.6%). In southern Tanzania, point prevalence of anemia among pregnant women was 46.3%. We determined biomarkers associated with anemia among pregnant women in Mbeya region to determine the source of the problem.

Methods: A cross sectional study was conducted among pregnant women aged 15-49 years with gestation of 28 weeks in Mbeya region. From the 7 districts; 44 health facilities were purposively selected and 419 pregnant women were systematically randomly selected. A semi-structured questionnaire was used to collect socio-demographic information, blood samples were tested for hemoglobin and Micronutrient Biochemical Analyses and their Mid Upper Arm Circumference measurements. Bivariate and multivariate modified Poisson regression model were fitted to determine the association between anemia status, biomarkers and hemoglobin levels.

Results: Prevalence of anemia among the pregnant women was 25% among the 419 pregnant women. More than 70% had only primary level education and 80% were self-employed. A strong association was found between anemia status and deficient serum ferritin levels (APR=2.25, 95%CI (1.59-3.21)), compared to those with normal ferritin levels. Pregnant women with deficient iron levels showed 3.32 (ARR=3.317, 95%CI: 1.117-9.853) times the risk of developing lower hemoglobin levels (less than 10g/dl) compared to those who have normal Iron levels. Pregnant women with vitamin A levels deficiency had 3.58 (ARR, 3.583, 95%CI: 0.999-12.857) times the risk of developing low levels of hemoglobin compared to pregnant women with normal level of vitamin A.

Conclusions: Anemia observed in pregnant women in Mbeya was due to nutritional deficiencies. Emphasis should be made on encouraging them to take foods rich in iron, folate and vitamin A and adherence to iron and folic acid supplements so as to prevent anemia during pregnancy.