Rethinking Race In Medicine: ACOG Removes A Race-Based Cutoff For Anemia In Pregnancy

Amid a reckoning over race-based protocols in medicine, the American College of Obstetricians and Gynecologists (ACOG) has eliminated a threshold that defined iron-deficiency anemia in pregnancy differently for Black women than for women of other races.

The disparity in treatment stems from the 1990s, when population-based studies showed Black women had lower hemoglobin levels but not other indications of iron deficiency. That became a rationale for setting a lower trigger for treatment of anemia for Black women than for other women. But in its revised guidance document, the ACOG acknowledges that a race-based standard could lead to undertreatment of anemia in Black pregnant women and expose them to greater risk of complications in childbirth or postpartum.

During pregnancy, blood volume rises, and women need more iron to create hemoglobin, a blood protein that carries oxygen throughout the body. Untreated anemia in pregnancy can lead to a greater need for blood transfusions during delivery and raises the risk of preeclampsia, cesarean delivery, preterm birth, and maternal death.

The ACOG’s revised “Anemia in Pregnancy” practice bulletin represents just one step in a national reconsideration of race in medicine, a focus on a contemporary understanding of social disparities and health impacts of racism, rather than seeing race through a biological lens.

In August 2020, the ACOG was among two dozen medical organizations involved in obstetrics and gynecology that issued a joint “Collective Action Addressing Racism” and committed to “transformational change” in response to historic and persistent racism in health care.

ACOG committees had begun reviewing past documents with an “equity framework” when the anemia practice bulletin came up for routine review, says Anjali Kaimal, a maternal and fetal medicine physician at Massachusetts General Hospital and chair of the ACOG committee on obstetric clinical practice guidelines. “We want to be sure we are equitably providing care,” she says.

Algorithms May Lead To Health Inequities

Race-based medical protocols and algorithms have existed for decades, but their use became part of the national conversation around racial justice with the August 2020 publication of a New England Journal of Medicine (NEJM) article that cited 13 race-based algorithms in eight fields of medicine. The authors suggested that such algorithms may contribute to health inequities, such as delayed treatment.

In obstetrics, the issue is especially resonant. The US has the highest rate of maternal mortality among 11 high-income countries, and Black women are about three times more likely to die in pregnancy, childbirth, or postpartum than White women.

The NEJM article called out a commonly used tool to predict the success of vaginal birth after cesarean (VBAC), which gave lower scores to Black and Hispanic women. Black women have higher rates of cesarean section (35.9 percent compared to 30.7 percent for White women in 2019) and a race-based predictive tool “could exacerbate these disparities,” the authors said.

Its creators, a team of researchers affiliated with the National Institutes of Health-funded Maternal-Fetal Medicine Units Network, have since updated the VBAC tool to remove race as a factor.

The NEJM article caught the attention of Rebecca Feldman Hamm, a maternal-fetal medicine physician at Penn Medicine and an assistant professor at the University of Pennsylvania. She thought of the anemia cutoffs, which were not mentioned among the article’s highlighted race-based algorithms. She recalled serving on an internal hospital committee that adopted the protocol when she was a medical resident. “I didn’t fully understand the implications of that” at the time, she says.

Hamm decided to take an evidence-based approach to reevaluating the cutoff. She and her colleagues analyzed data that had been collected prospectively for a different University of Pennsylvania study of pregnant women with hemoglobin levels less than 11 grams per decaliter (g/dL). The 1,369 women in the study delivered at the Hospital of the University of Pennsylvania from 2018 to 2019; 79 percent of them were Black.

Using race-based cutoffs, all women with levels below 10.2 g/dL in the third trimester would be treated for anemia regardless of race. However, only non-Black women in the range of 10.2 to 11.0 g/dL would be treated, while Black women in that range would not. That led to a difference in the health of women arriving for labor and delivery.

After adjusting for body mass index, age, and other possible confounders, they found that Black women with hemoglobin in the range of 10.2 and 11.0 g/dL during the third trimester had a 65 percent greater likelihood of presenting in labor with mild anemia (hemoglobin below 11 g/dL) than non-Black women who had been in that range during the third trimester. There was no significant disparity for Black women who had hemoglobin levels below 10.2 g/dL during pregnancy, which triggered iron treatment.

“Just because Black women are more likely to have lower hemoglobin, that doesn’t necessarily mean those women don’t deserve treatment and that treatment wouldn’t potentially improve outcomes,” Hamm says.

The study wasn’t large enough to detect a racial difference in blood transfusions during delivery. But overall, women with hemoglobin levels below 11 g/dL were more likely to require a transfusion during or following delivery.

Hamm presented the research at February 2021 conference of the Society of Maternal-Fetal Medicine, with a provocative title: “Racially inequitable definitions of anemia perpetuate disparities in maternal outcomes: time to change.”

“People were very interested in the data,” she says. “They were very excited to see someone addressing these issues.” After the “Research Letter” was published online in Obstetrics & Gynecology in June, the ACOG committee incorporated the new findings into the revised practice bulletin, which was released about six weeks later.

It Began As An Effort To Avoid Overtreatment

The race-based threshold dates to a 1993 report by the Institute of Medicine (IOM) (now the National Academy of Medicine), which noted that “[t]he average hemoglobin concentration of healthy blacks is lower than that of other races,” based on national population data collected by the Centers for Disease Control and Prevention.

The IOM panel expressed concern about the overtreatment of Blacks for anemia and noted that Black women and children with mild anemia often didn’t respond to iron treatment. “The use of separate hemoglobin criteria for blacks could be seen as racially stigmatizing, but the advantage of fewer false-positive diagnoses is a strong argument for making an appropriate downward adjustment in hemoglobin and hematocrit cutoff values,” the report said.

In a 2008 practice bulletin, the ACOG cited the IOM report as it suggested the lower threshold for Black women, saying that “applying the same criteria to all women could inappropriately classify almost 30% of African American women as iron deficient.”

The new practice bulletin states, “However, since the etiology of these disparities is unknown and using a different standard may result in a failure to identify and treat people at risk for adverse pregnancy outcomes related to anemia, the same criteria should be used for all populations.”

“It says a lot about ACOG that they were willing to act so quickly in response to new data” to revise the practice bulletin, Hamm says.

A Commitment To A Transformation In Medicine

It’s unknown how many hospitals have used a different anemia cutoff for Black pregnant women (Kaimal notes that Mass General never used race-based cutoffs.), so it’s difficult to gauge the potential impact of the change in the practice bulletin. (The revision also incorporated other clinical updates, such as new findings on the use of intravenous iron.)

Still, it sends an important message, says Rachel Bervell, a family and community medicine resident at Boston Medical Center who is co-founder of the Black Ob/Gyn Project. The Instagram site began as a social media space to connect Black medical residents, but it now has a broader audience of 20,000 followers.

“To be frank, it’s racism,” Bervell says, who is also on the organizing team of the Institute for Healing and Justice in Medicine, which issued a report calling for the abolition of biological race in medicine. “Race should be taken out of these algorithms because it can cause huge issues in making sure that our patients are getting the care that they need.”

Bervell also points to new language in a revised ACOG practice bulletin on management of uterine leiomyomas, or fibroids, which are more common and more severe in Black women. “These observed differences are likely due in large part to systemic racism, as well as to social determinants of health…” states the bulletin, which was published in June 2021. “Experiences of racism can delay women from seeking care for leiomyoma symptoms until they are severe, and racial bias in medicine at the systemic and individual levels may affect the quality of diagnosis and treatment they receive.”

That represents an important reexamination of race and racism, Bervell says. “When I see this type of change in medicine, it reminds me that we might be slow, but we can have transformation for the betterment of our patients.”