1052 Do adverse neonatal outcomes differ by anemia type among women with pre-existing diabetes?

Abstract

The etiology of anemia in diabetes is likely mediated through a combination of dietary iron deficiency, functional iron deficiency due to IL-6, erythropoietin deficiency, and drug exposure. We sought to determine whether adverse pregnancy outcomes differ by anemia sub-type among pregnant women with pre-existing diabetes. We conducted a cohort study of pregnant patients with type 1 or 2 diabetes who received care at a tertiary referral center from 2007-2017. Patients with a known hemoglobinopathy and macrocytic anemia were excluded. Women diagnosed with a microcytic or normocytic anemia at any point in pregnancy were compared to those with no documented anemia as the referent group. The primary outcome was a neonatal composite morbidity index including polyhydramnios, preterm birth, neonatal hypoglycemia, Neonatal Intensive Care Unit admission, and respiratory distress syndrome. Secondary outcomes included individual components of the composite. Logistic regression was used to control for potential confounding variables including race, nulliparity, and diabetes type. Of 450 patients, 3 were excluded for having macrocytic anemia. Of the remaining 447, 162 (36%) did not have anemia during pregnancy, 85 (19%) had microcytic anemia, and 200 (45%) had normocytic anemia. Demographic characteristics were similar between groups except those without anemia were more likely to be nulliparous and those with microcytic anemia were more likely to be obese or Black. There were no significant differences in the neonatal composite index by anemia sub-type after controlling for confounding variables. Normocytic anemia was associated with early preterm delivery (aRR 4.8; 95% CI 1.45-15.2). There were no differences in other secondary outcomes by anemia sub-type. Normocytic anemia is the predominant sub-type among women with diabetes in pregnancy, and it is associated with an increased risk of early preterm birth.