Intravenous Iron Infusion in the Treatment of Iron Deficiency Anaemia Following Bariatric and Metabolic Surgery and Correlation with Gynaecological Disorders: Retrospective Review of Experience from a Tertiary Centre

Background and Objectives: Iron deficiency anaemia (IDA) is a common consequence of bariatric and metabolic surgery (BMS). Women are at higher risk, and some patients cannot tolerate oral iron. This study aimed to report the demographics of patients with IDA that required iron infusion post-BMS and to investigate risk factors including gynaecological dysfunction. Materials and Methods: The medical records for all patients (n = 383) post-BMS at a large tertiary centre from January 2017 to December 2024 were reviewed, and those who received intravenous iron infusion (n = 32) for IDA were included. The criteria for iron infusion were ferritin < 50 µg/L or intolerance to oral iron. Demographic information including co-morbidities—gynaecological and other—age, pre-operative weight, body mass index (BMI), and ferritin levels were collected to investigate possible risk factors for IDA. Results: Thirty-two patients, all female, received one or more parenteral iron infusions. Eighteen had surgery locally; 14 had surgery elsewhere. Operations varied and included 14 Roux-en-Y gastric bypasses, 14 sleeve gastrectomy’s, and 4 gastric bands or other procedures. Eleven patients had a history of gynaecological disorders. Pre-infusion ferritin levels in the cohort with gynaecological disorders versus the cohort without were lower (median 11.0 vs. 14.5 µg/L), with a shorter time to presentation (median 6.9 vs. 10.2 years), and more patients requiring >2 infusions for resolution of symptoms (36.4% vs. 9.5%). Conclusions: Locally, 95% of our patients did not require iron infusion post-BMS. Eighty percent of those who did require iron infusion responded to ≤2 infusions. Women with a history of gynaecological disorder who underwent BMS required a significantly higher number of iron infusions and presented with symptoms sooner post-operatively vs. those without gynaecological disorders, particularly following Roux-en-Y gastric bypass. This is an important observation to consider both pre- and post-operatively for patients undergoing bariatric surgery, and additional well-designed studies that investigate this further are needed.