Objective To compare prevalence of anaemia and haemoglobin (Hb) levels in pregnant women in the five Brazilian regions, before and after the fortification of flours with iron.
Methods A repeated cross-sectional panel study was carried out by public healthcare services located in the five Brazilian regions. Retrospective data were collected from medical records. Pregnant women were divided into two groups: before-fortification (delivery before June 2004) and after-fortification (last menstrual period after June 2005). The sample included 12 119 records. Anaemia was defined as Hb<11 g/dl. We used χ2, Student t test and logistic regression, with significance level of 5%.
Results Anaemia was lower after-fortification of flour (p<0.05). The prevalence dropped from 25% to 20% after-fortification (p<0.001). Hb level also was significantly higher after-fortification (p<0.001). The findings showed different sized reductions between regions. In the Northeast and North, where the prevalence of anaemia were high, a significant drop after-fortification was found: from 37% to 29%, and 32% to 25%, respectively. In the Southeast and South, whose prevalence was low before-fortification, there were smaller decreases: from 18% to 15%, and 7% to 6%, respectively. Logistic regression showed that group, geographic region, marital status, gestational trimester, initial nutritional status and previous pregnancy were associated with anaemia (p<0.05).
Conclusions The prevalence of anaemia in pregnant women is still high in the Northeast, North and Midwest of Brazil. However, the decrease in anaemia prevalence and increase in Hb levels suggest a positive effect of fortification of flour to control of iron deficiency. In should be noted that a number of other variables not studied may have contributed to this result.