Title of project: Causes of iron deficiency anemia in children less than 12 years old at Cooper University Hospital and their response to intravenous iron Background: Iron deficiency anemia (IDA) is the most common type of anemia in children. Even among industrialized countries like the US, IDA affects many children. Serious adverse outcomes can occur in children with IDA including, cognitive and motor neurodevelopmental delays which may be irreversible. While poor oral intake tends to be the focus of screening and preventative measures, additional causes of IDA include malabsorption from gastrointestinal abnormalities, medications that decrease iron absorption, parasitosis, genitourinary loss, and blood loss. Menorrhagia is a common cause of IDA among adolescents. The average age of menarche for adolescent girls is 12.43 years. Therefore, on data evaluation for the cause of IDA among patients aged 1-21, menstrual bleeding was overrepresented. Objective: This sub-analysis of a single center retrospective chart review analyzed the causes of IDA among children less than 12 years of age at Cooper University Hospital and their response to intravenous iron treatment. Methods: Data on all patients 1-12 years old who received intravenous iron infusions at Cooper University Hospital for IDA between 2016 and 2021 was analyzed. Descriptive statistics on the etiology of IDA and paired t-tests comparing pre-infusion hematologic parameters (hemoglobin, RDW, RBC, MCV, iron, ferritin, TIBC, percent saturation) to post-infusion values were conducted. Results: From the 150 patients included in the original study, 26 patients were 12 years of age or younger. The causes of IDA among these patients included inadequate dietary intake (65.4%), inflammatory bowel disease (15.4%), menorrhagia (15.4%) and one patient with factor II deficiency (3.8%). These patients required between one to eleven infusions to return to normal lab values. When comparing pre-infusion to post-final infusion lab values, there was significant improvement in all values (ferritin, iron, hemoglobin, MCV and RBCs) except total iron binding capacity, RDW and percent saturation. Discussion: Inadequate dietary intake was the most common cause of IDA in children less that 12 years old treated at Cooper University Hospital. Other causes included inflammatory bowel disease, menorrhagia and factor II deficiency. In contrast, the most common cause of IDA in children 12 and older was menorrhagia. Childhood food insecurity has been linked to IDA among low-income patients in the United States. Despite food assistance programs and adequate dietary education, patients continue to remain iron deficient. The current first-line therapy at Cooper University Hospital is oral iron supplementation. However, many patients fail the oral iron trial due to non-adherence, children spitting up or refusing to take the medication, and gastrointestinal side effects. Many pediatric patients in our clinic population are on NJ state insurance which requires a failed oral iron therapy trial prior to qualifying for coverage of intravenous iron. Yet, in a previous retrospective study completed in our clinic, intravenous iron has proven to be effective and safe, with fewer side effects and better adherence. For many patients, especially infants and toddlers, intravenous iron may provide a quicker cure for IDA, preventing irreversible neurodevelopmental delays. We propose that treatment with oral iron and intravenous iron should both be considered for first-line therapies and should be a shared decision between parents and providers.