New Study Examines the Cause of Racial Disparities in C-sections

It has been well documented that Black women receive C-sections at higher rates than their white counterparts, but the root cause of this discrepancy has been unclear. Are Black women more likely to need the procedure? Or are they receiving more C-sections — which can be lifesaving for both mother and baby but can introduce a host of complications — for reasons unrelated to medical need, like patient preference or provider discretion?

“There are a number of different possible explanations, and we realized we had the tools to try to get at which of these explanations was the most likely,” says Janet Currie *88, Princeton professor of economics and public affairs, who led the research.

Currie has spent much of her career studying racial disparities in health care and collaborated with two researchers she once advised at Princeton to address this question. The trio of Currie, Molly Schnell *18, and Adriana Corredor-Waldron, assistant professors of economics at Northwestern University and North Carolina State University, respectively, collected and analyzed data on nearly 1 million births in New Jersey across 68 different hospitals. Schnell completed her Ph.D. with Currie, while Corredor-Waldron worked with Currie as a postdoctoral researcher from 2019 to 2022.

“If you’re a doctor and you regard someone as high risk, then you might be more aggressive with interventions. There could be kind of a self-perpetuating mechanism.”

Janet Currie *88

Princeton professor of economics and public affairs, who led the research

They first used a machine learning algorithm to predict the risk a woman has of needing a C-section based on medical history. Even after controlling for socioeconomic factors like Medicaid coverage and education level, they found that Black mothers are 20% more likely to receive a C-section than white mothers of the same risk level. The difference was most pronounced in the lowest-risk category, suggesting that Black women are disproportionately receiving unnecessary C-sections.

To account for the possibility that Black mothers may choose to undergo C-sections more frequently than white mothers, the researchers limited their analysis to unscheduled C-sections, which are given during labor emergencies and are not a matter of preference. They also compared C-section rates among Black and white patients treated at the same hospital and by the same clinician. They found the discrepancy still persisted, indicating that even the same doctors are treating Black patients differently.

Finally, the researchers considered whether there might be risk factors not included in medical records that doctors rely on when deciding whether to opt for a C-section. They devised a creative test for this hypothesis: looking at C-section rates when the hospital’s C-section operating room is occupied. Though it might be inconvenient for a hospital to prepare a different operating room for a C-section, they would do so without hesitation if there’s an urgent medical need.

“If everything is driven by medical risk, then [hospital] capacity shouldn’t matter,” says Currie. In fact, if Black mothers need unscheduled C-sections more often than white mothers, the disparity should actually grow when the C-section suite is occupied; Black mothers would be the first to receive the surgery even when the hospital is less equipped to provide it.

However, Currie and her team found that the disparity vanishes when the operating room is in use. This suggests, according to the researchers, that the racial gap is driven by doctors choosing to perform unnecessary C-sections on low-risk Black mothers when it’s less expensive or more convenient for the hospital to do so.

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Janet Currie *88

Denise Applewhite / Princeton University

Their motives are unclear. The medical bill for a C-section is higher than that of a vaginal birth, a financial incentive that doctors might be disproportionately extracting from Black mothers. Alternatively, they may be trying to preempt negative birth outcomes for Black mothers, even as it ultimately predisposes them to greater risk down the road.

“If you’re a doctor and you regard someone as high risk, then you might be more aggressive with interventions,” says Currie. “There could be kind of a self-perpetuating mechanism.”

To mitigate this pattern, doctors could be asked to justify in writing their decision to perform a C-section, Currie suggests, an approach that’s lowered rates of the procedure for low-risk individuals in some contexts. Doctors could also use an algorithm similar to the one used by the researchers to receive a risk score predicting the likelihood a C-section is warranted, which could inform treatment decisions.

“We don’t think it is an appropriate thing to reduce C-sections across the board,” Currie emphasizes, but “we would like to discourage [doctors] from doing unnecessary surgeries on people.”