Suplementação de vitaminas e sais de ferro na gestação: associação com Diabetes Mellitus Gestacional

Abstract

In the gestational period, women need more energy intake and also have a greater demand for micronutrients. Although adequate diet remains the preferred means of meeting such demands, some needs are difficult to achieve in pregnancy only with a healthy diet. To overcome this problem, some countries fortify selected foods or recommend the use of supplements in the antenatal period. In Brazil, the Ministry of Health promotes some actions and programs of micronutrients supplementation that cover the group of pregnant women aiming to reduce nutritional deficiencies. Current guidelines of the World Health Organization and the Brazilian Ministry of Health recommend the routine supplementation of iron and folic acid for all pregnant women, in order to meet the physiological needs of these micronutrients. However, despite the benefits of this practice for pregnant women, some studies have suggested that iron supplementation in non-anemic women early in their pregnancy may have adverse effects, such as an increased risk of developing gestational diabetes.Using data from the 2015 Pelotas Birth Cohors, this thesis aimed to evaluate the use of iron and folic acid in each trimester of pregnancy , assessing the existence of socioeconomic inequalities in their use; and to evaluate whether non-anemic pregnant women who used iron supplements were at a higher risk of developing gestational diabetes mellitus than those who did not use this supplementation. Results showed that 30% of the women evaluated did not use folic acid and iron supplementation during pregnancy. The poorest women presented a higher prevalence of iron intake. However, folic acid showed a higher prevalence of use among the richest women, indicating socioeconomic inequality against the poorest ones. The second article, also with data from the 2015 Birth Cohort, and the third article, a systematic review of the literature, evaluated the association between the iron supplements intake among pregnant women and gestational diabetes. The results suggested that iron intake among non-anemic pregnant women does not increase the risk of developing gestational diabetes. A fourth article evaluated the validity of woman’s self-report of anemia and the iron supplements intake during pregnancy. Although their sensitivity and specificity are not high, the self-report of anemia and iron supplements intake may be useful in population-based studies of postpartum women in medium-sized Brazilian cities with social and antenatal care contexts similar to those of Pelotas.