Rationale of a Cohort Study on Risk of Obstetrical Outcomes Associated with Iron Supplementation during Pregnancy

Abstract

Background: Anemia is one of the most widely prevalent disorders, affecting the lives of almost half a billion women of reproductive age, contributing to over 100,000 maternal and almost 600,000 perinatal deaths (mostly through pre-term delivery, low birth weight) each year. Increased risk of infant mortality and reduced cognitive development and reduced energy levels which affect productivity in adults are cited. During pregnancy increased requirements, inadequate intake of iron and other micronutrients and parasitic (malaria, hookworm) as wells as bacterial (mostly urinary tract) infections are the main causes. In order to reduce such maternal and neonatal burden, it has been worldwide admitted to adopt cost-effective preventive interventions during pregnancy, including iron-folic acid supplementation, de-hookworming medication and anti-malarial prevention or treatment. Intestinal absorption of iron is limited by a lot of factors including bioavailability, iron status of the woman, substances accompanying or contained in diet, chelating agents such as diet fibers or calcium salts. Any supplementation put additional constraint in terms of absorption. Unabsorbed iron is known to have pro-oxidant properties likely to induce production of free radicals. These in turn might induce oxidative stress accountable for in generation of many obstetrical outcomes. This potential link between oxidative stress resulting from free radicals hyperproduction induced by non absorbed iron and harmful maternal/perinatal conditions is rarely questioned by searchers. Objectives: To determine overall (food and supplemented) iron consumption, iron and oxidative status in a cohort of pregnant women and to seek associations between findings and adverse obstetrical outcomes. Methods: At the University Clinics of Kinshasa, we designed a protocol for a prospective cohort study dealing with clinical and biochemical parameters of oxidative stress among pregnant women iron supplemented. Women with a single pregnancy not exceeding 19 weeks without obvious pathology, regardless of age and parity, were eligible for inclusion in the study. Conclusion: This study is expected to assess consequences of oral iron supplementation during pregnancy in terms of obstetrical outcomes associated with oxidative stress linked to unabsorbed iron.