(451) Effectiveness of intravenous ferric carboxymaltose for severe anemia in the late third trimester

Thursday, January 30, 2025

4:00 PM – 6:00 PM

Submitting Author and Presenting Author(s)

Christine E. Henricks, DO (she/her/hers)

Fellow
University of Texas Southwestern Medical Center
Dallas, TX, United States

Coauthor(s)

Rachel C. Schell, MD (she/her/hers)

University of Texas Southwestern Medical Center
Dallas, TX, United States
Catherine Y. Spong, MD

Professor and Chair
University of Texas Southwestern Medical Center
Dallas, Texas, United States
Elaine L. Duryea, MD

Associate Professor
University of Texas Southwestern Medical Center
Dallas, Texas, United States

Objective: Iron deficiency anemia is associated with adverse pregnancy outcomes. Prior studies have shown reduced morbidity with intravenous (IV) iron therapy, but the optimal timing of administration is unknown. The objective of this study was to evaluate whether administration timing of IV ferric carboxymaltose in the late third trimester impacts maternal hematologic indices and outcomes.

Study Design: A retrospective cohort study was conducted from October 2020 to May 2024 of IV ferric carboxymaltose for the treatment of severe anemia in the third trimester, defined by a hemoglobin < 8 g/dL or hematocrit < 25%, plus iron < 40 mcg/dL or ferritin < 15 ng/mL. Eligible patients received two infusions one week apart, regardless of gestational age at diagnosis. Patients beginning treatment early, defined as < 36 weeks gestation (WGA), were compared to those with late treatment starting ≥ 36 WGA. Mann-Whitney U and Chi-squared tests were used for statistical analysis.

Results: Of 129 patients, 101 received IV iron < 36 weeks (early) and 28 ≥ 36 weeks (late). Hemoglobin at diagnosis of severe anemia was not different, median 7.3 [7.0,7.7] g/dL in early cohort and 7.6 [7,7.8] g/dL in the late cohort (p=0.121). The median rise in hemoglobin between diagnosis and delivery was 3.8 [2.7, 5.2] g/dL for the entire population. There was no difference in gestational age at delivery between the cohorts. Importantly, hemoglobin levels at delivery were not different between the early (11.2 [10.5,12.0] g/dL) and late (10.6 [9.6,11.2] g/dL) cohorts (p=0.251). The incidence of peripartum transfusion was not different, 5.0% in the early cohort and 3.6% in the late cohort (p=0.759).

Conclusion: Patients receiving IV ferric carboxymaltose for severe anemia ≥36 WGA demonstrated similar improvements in hemoglobin levels compared to those receiving treatment earlier in gestation and were no more likely to require transfusion at delivery. IV ferric carboxymaltose should not be withheld in the late third trimester based on perceived futility with advancing gestational age.