36 Racially inequitable definitions of anemia perpetuate disparities in maternal outcomes: time to change

Abstract

When defining anemia in pregnancy, ACOG recommends lower hemoglobin (Hb) cutoffs for Black vs. non-Black women (3rd trimester Hb<10.2g/dL in Black women; <11g/dL in non-Black women). We aimed to determine the impact of this definition on Hb at delivery and blood transfusion rates. We performed a prospective cohort study of women with antepartum Hb<11g/dL delivering at our institution from 2018-2019. During the study period, treatment of anemia with iron supplementation occurred per race-based recommendations. For example, using these definitions, Hb=10.3g/dL in a non-Black woman warranted iron, while the same Hb in a Black woman did not. Antepartum anemia was categorized by severity (Hb<10.2g/dL; 10.2-11.0g/dL) and analyses stratified by self-reported race (Black; non-Black). The Figure depicts the cohort (n=1455) by antepartum Hb and race. 51.9% of Black women had an antepartum Hb 10.2-11.0g/dL; unlike the rest of the cohort, these women did not meet the race-based anemia cutoff for treatment. As a result, 41.0% of Black women with antepartum Hb 10.2-11.0g/dL remained <11g/dL at delivery compared to 26.4% of non-Black women with antepartum Hb 10.2-11.0g/dL (p<0.001). This equates to 75% increased odds of presenting for delivery with Hb<11.0 for Black vs. non-Black women even when controlling for age and parity (aOR 1.75 95%CI[1.31-2.32]). Importantly, the transfusion rate was the same among Black and non-Black women who presented for delivery with Hb<11g/dL (8.4% vs. 9.4%, p=0.76), and all women with Hb<11g/dL at delivery were at 3 times higher odds of transfusion when compared to those ≥11g/dL (aOR 3.43 95%CI[2.09-5.65]). Hb<11g/dL at delivery, regardless of race, is a risk factor for transfusion, and Black women are more likely to present to delivery with Hb<11g/dL due to differential treatment of anemia by race. If these Black women had been treated, 1 in 7 may have Hb≥11g/dL by delivery, significantly decreasing transfusion risk. Race-based treatment thresholds need to change to eradicate systemic inequities that perpetuate disparities in maternal morbidity.