Utility of Reticulocyte Hemoglobin Equivalent in Screening for Iron Deficiency in Pregnancy

Lylach Haizler-Cohen; Haleema Saeed; Valencia Quiett; Gurpinder Kaur; Eshetu A. Tefera; Samrawit Gizaw; Richard Verstraete; Michael Auerbach; Nicholas Hazen

doi:10.1055/a-2419-9404

American Journal of Perinatology, Table of Contents

Am J Perinatol 2025; 42(07): 834-841
DOI: 10.1055/a-2419-9404

SMFM Fellowship Series Article

Utility of Reticulocyte Hemoglobin Equivalent in Screening for Iron Deficiency in Pregnancy

Authors

Lylach Haizler-Cohen

¹Department of Obstetrics and Gynecology, MedStar Washington Hospital Center, Washington, District of Columbia
Haleema Saeed

¹Department of Obstetrics and Gynecology, MedStar Washington Hospital Center, Washington, District of Columbia
Valencia Quiett

²Bloodless Medicine and Surgery Program, MedStar Georgetown University Hospital, Washington, District of Columbia
Gurpinder Kaur

¹Department of Obstetrics and Gynecology, MedStar Washington Hospital Center, Washington, District of Columbia
Eshetu A. Tefera

³Department of Biostatistics, MedStar Health Research Institute, Hyattsville, Maryland
Samrawit Gizaw

³Department of Biostatistics, MedStar Health Research Institute, Hyattsville, Maryland
Richard Verstraete

²Bloodless Medicine and Surgery Program, MedStar Georgetown University Hospital, Washington, District of Columbia
Michael Auerbach

⁴Department of Medicine, Georgetown University School of Medicine, Washington, District of Columbia
Nicholas Hazen

⁵Department of Obstetrics and Gynecology, MedStar Georgetown University Hospital, Washington, District of Columbia

Abstract

Objective

Ferritin, commonly used for diagnosing iron deficiency (ID) in pregnancy, is limited by high cost and false elevations during inflammation. Reticulocyte hemoglobin equivalent (Ret-He), an alternative marker for ID, is unaffected by inflammation and analyzed on the same collection tube as the standard complete blood count (CBC). We aimed to determine the accuracy of Ret-He in detecting ID in pregnancy compared to ferritin in a U.S. cohort.

Study Design

This prospective cohort study enrolled 200 pregnant participants, recruited in any trimester if a CBC was drawn as part of routine prenatal care. For those who agreed to participate, Ret-He and ferritin were collected concurrently with the CBC. ID was defined as ferritin level below 30 ng/mL. Patients were classified into three groups based on hemoglobin and ferritin results to determine the severity of ID: no ID, ID alone, and ID anemia (IDA). Four participants with anemia but normal ferritin were excluded. Receiver operating curve analysis, including the area under the curve (AUC), was performed to assess the accuracy of Ret-He in detecting ID. A one-way ANOVA (analysis of variance) with post-hoc analysis was used to compare differences in Ret-He between the three groups of ID severity.

Results

The prevalence of ID in our cohort was 82% (161/196). The AUC for Ret-He was 0.65 (95% confidence interval: 0.55–0.75), indicating suboptimal discrimination between patients with and without ID. Ret-He was significantly different among the three groups (p < 0.001). In post-hoc analysis, Ret-He was significantly lower in the IDA group compared to the ID group (p < 0.001) but there was only a trend of lower Ret-He in the ID group compared to the non-ID group (p = 0.38).

Conclusion

Ret-He has low accuracy in diagnosing ID in pregnancy. It may be useful in detecting severe ID resulting in anemia but not a mild iron-deficient state resulting in ID only.

Key Points

The prevalence of ID in our cohort was 82%.
Ret-He has low accuracy in diagnosing ID in pregnancy.
Ferritin is preferable when readily available.

Keywords

anemia - ferritin - iron deficiency - pregnancy - reticulocyte - reticulocyte hemoglobin equivalent

Full Text

References

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