Anemia in Brazilian pregnant women before and after flour fortification with iron

Abstract

Objective: To compare prevalence of anemia and hemoglobin (Hb) levels in Brazilian pregnant women before and after flour fortification with iron.

Methods: A repeated cross-sectional panel study of public health care centers of municipalities in the five Brazilian regions was conducted. Retrospective data were obtained from 12,119 medical records of pregnant women distributed in two groups: before fortification (delivery prior to June 2004) and after fortification (date of last period after June 2005). Anemia was defined as Hb<11.0 g/dl. Hb levels according to gestational age were assessed using two references from the literature. Statistical analysis was carried out using chi-squared tests, Student's t tests, and logistic regression, with a significance level of 5%.

Results: In the total sample, prevalence of anemia fell from 25% to 20% after fortification (p<0.001). However, important regional differences were evident: while significant reductions were seen in the Northeast (37% to 29%) and North (32% to 25%) regions, where pre-fortification prevalence was high, smaller reductions were seen in the Southeast (18% to 15%) and South (7% to 6%) regions, where prevalence was low. Hb levels according to gestational age were slightly higher in the first months of pregnancy and lower after the third or fourth months, depending on the reference used. Logistic regression analysis showed that group, geographic region, marital status, trimester of pregnancy, initial nutritional status, and prior pregnancy were associated with anemia (p<0.05).

Conclusions: Prevalence of anemia decreased after fortification, but remains high in the North and Northeast regions. Although fortification may have played a role in this favorable outcome, the contribution of other public policies implemented during the studied period should also be considered.