Background: Iron deficiency anemia (IDA) in pregnancy is common in the United States, with an overall prevalence of 18%. ACOG and CDC guidelines recommend screening for anemia be done at the first prenatal visit with a CBC. IDA in pregnancy is associated with several adverse fetal and maternal health outcomes, including pre-term birth and low birth weight. Studies are just beginning to emerge describing racial disparities associated with assessment and management of IDA in pregnancy. Our primary objective in this study is to investigate the screening practices for anemia in pregnant women at our institution. Further objectives include investigating potential racial disparities in screening practices and management for anemia in pregnant women.

Methods: We performed a retrospective cohort study of all pregnant women, aged 13-50 years old, who delivered at the University of Michigan (UM) between July 2015 and January 2022, and who received prenatal care at UM beginning the first trimester of pregnancy. After IRB approval, data were collected from the UM electronic medical record, MiChart. Inclusion in the cohort was based on CPT codes for delivery; first trimester visit was defined based on calculation from last menstrual period to 13 weeks of gestation. We used a t-test to compare mean hemoglobin (Hgb) and mean corpuscular volume (MCV) in Caucasian and African American women. We defined anemia as Hgb <10.5 g/dL during any point in pregnancy. We used Chi-square analysis to compare the proportion of Caucasian and African American women screened for anemia with Hgb and screened for iron deficiency with ferritin and transferrin saturation. Chi-square analysis was also used to compare the proportion of women prescribed iron supplementation.

Results: A total of 16,073 pregnant women were included in the study, with 1,781 (11.08%) self-reported African Americans, 11,590 (72.11%) Caucasians, 1,472 (9.16%) Asians, and 1,230 (7.65%) women of other races/unknown. While screening for anemia was very common in our cohort, Caucasian women were slightly more likely to be screened for anemia than African American women (98.88% vs. 97.47%, p <0.001); see Table 1 below. Overall, 23.87% of women in our cohort were anemic at some point during pregnancy. Anemia was more common among African American women compared to Caucasian women (39.79% vs 21.41%, p <0.001). The mean Hgb was significantly higher in Caucasians versus African Americans (11.63 g/dL, SD 1.58 vs. 10.84 g/dL, SD 1.62, p <0.001). Mean MCV was lower in African Americans than Caucasians (85.94 fL, SD 6.63 vs. 89.04 fL, SD 5.12, p <0.001). African American women were more likely to be tested for iron deficiency compared to Caucasian women using ferritin (1.12% vs. 0.53%, p <0.001), and transferrin saturation (1.12% vs 0.44%, p <0.001). In terms of anemia management, 31.05% of patients overall were prescribed iron supplementation (oral or IV forms). African American women were more likely to be prescribed supplemental iron compared to Caucasian women (45.65% vs. 28.81%, p <0.001).

Conclusion: Overall screening for anemia among pregnant women is very common among patients in our cohort, in congruence with guideline recommendations. Even though only a small proportion of patients did not have a Hgb checked during pregnancy, African American women were less likely to be screened for anemia during pregnancy compared to Caucasian women. In our cohort, pregnant African American women were more likely to be anemic, with a lower mean Hgb level and MCV compared to Caucasian women. Interestingly, although approximately one in four women were found to be anemic overall, less than 1% of women in our cohort had laboratory testing with ferritin or transferrin saturation to further work up iron deficiency. Despite this, nearly one third of patients received a prescription for iron supplementation. This suggests a frequent practice at our institution of empirically prescribing iron supplementation in the absence of laboratory work up for iron deficiency, especially among African Americans. Next steps include further evaluation as to whether this is an effective approach to treating anemia in pregnancy, or whether additional anemia work up is warranted in this population.

Sood:Bayer: Membership on an entity's Board of Directors or advisory committees.

Author notes

Asterisk with author names denotes non-ASH members.

Sign in via your Institution