Routine Iron Supplementation during Pregnancy: Its Reflection on Iron and Oxidative Status in a Cohort of Pregnant Women in Kinshasa, DR Congo

摘要

Background:? Due to maternal and fetal physiologic demand , the rate along with amplitude of anemia is expected to rise over pregnancy. The iron and oxidative status also are expected to vary accordingly. It is thus assumed that iron supplementation will somewhat modify the profile observed in markers of iron and oxidative status of our series. Objectives : We aimed to measure variations of indices of iron and oxidative status of iron supplemented women over pregnancy. Methods : This is a prospective observational cohort of 74 pregnant women with singleton pregnancy whose baseline iron and oxidative status have been recently assessed at University Clinics of Kinshasa, DR Congo. Women with anemia (Hb < 10 g%) took iron for curative purposes (320 mg/day of ferric ammonium citrate) while the others received preventive iron supplementation (160 mg/day). Iron was associated with 15 mg folate/day. Nutritional iron intake was measured through a 24-hour recall using a questionnaire of common foods, including stuffs and habits likely to impede iron absorption. Biological parameters of iron and oxidative status included hemoglobin, hematocrit, ferritin, serum iron, transferrin, superoxide dismutase or SOD, uric acid, oxidized LDL and blood glucose. For statistical calculations we used t-test, chi-square test, ANOVAR and regression, the significance being stated at p < 0.05. Results : Trimester wise evolution of hematologic status in anemic women shows a rise in values of hemoglobin (+average 1 gr/dl) and hematocrit (+3%) throughout pregnancy, with significant change only between recruitment and 28 - 32 weeks. In non anemic women a significant decrease was observed, although levels remained normal. For ferritin (7.5 - 53 ng/mL from recruitment to term) and transferrin (107 - 157 g/L), significant rise was found in anemic women from recruitment to 28 - 32 weeks, while in non anemic notable change occurred only for transferrin (133 - 204 g/L). Serum iron significantly increased (53 - 83 μg/dL) from recruitment to 28 - 32 weeks in anemic women only. So, following supplementation, values of blood parameters tended to be similar for both goups at term. Non anemic women did not benefit from supplementation. SOD decreased and LDL values increased alongside supplementation. This represents a growing oxidant threat for both anemic and non anemic women. This could be related to iron overload and/or unabsorbed iron. Conclusion : Iron supplementation improved iron status in anemic women, not in non anemic. Differences that were significant between groups at recruitment disappeared by 28 - 32 weeks. Non anemic women did not benefit from supplementation. SOD decreased and LDL values increased alongside supplementation. This represents a growing oxidant threat for both anemic and non anemic women. This could be related to iron overload and/or unabsorbed iron. Doses of iron should be decreased (at least halved) and duration of treatment restricted to not more than 12 weeks.