How Social Determinants of Health Drive Maternal Health Disparities

Black women born in the US have a higher odds of preeclampsia than Black women who immigrated from other countries, according to new data from Johns Hopkins Medicine, indicating that other social determinants of health join race in perpetuating Black maternal health disparities.

Preeclampsia is a leading cause of maternal deaths, and particularly exacerbates Black maternal health disparities. Per CDC figures, Black women are between three and four times more likely to die from childbirth-related complications than their White counterparts. Higher rates of preeclampsia among Black women could account for part of that overall disparity.

According to Garima Sharma, the Hopkins study’s lead researcher and the director of cardio-obstetrics at the Johns Hopkins University School of Medicine, the conventional wisdom has stated Black women were at higher risk for poor birthing outcomes by virtue of their race.

But this latest study indicates a need to understand exactly why that is, Sharma said.

“We need to move beyond putting all the implications on a particular race without accounting for why that is, because in this study, it’s clear that Black women born outside the U.S. are less likely to have preeclampsia until they have been here for some time,” Sharma said in a press release.

Sharma and colleagues assessed medical records for some 6,000 women giving birth at Boston Medical Center between 1998 and 2016. Across Black, White, and Hispanic patients, cardiovascular risk was higher among those born in the US than those who immigrated here.

And among Black women, that also translated into a higher risk for preeclampsia if a patient was born in the US. Preeclampsia rates for US-born Black women came in at 12.4 percent, the researchers reported.

Black women born outside the US saw a 26 percent lower odds of experiencing preeclampsia than Black women born in the US.

What’s more, foreign-born Black women who had spent less time in the US experienced better odds of good birthing outcomes. Black immigrants who had lived in the country for less than 10 years had an 8.1 percent risk of preeclampsia, compared to the 8.8 percent risk for those who had lived in the US for longer than 10 years.

The Hopkins researchers didn’t dive into the reasons behind this nativity-related health disparity, but Sharma posited some social determinants of health factors could be at play.

“Immigrants come here to seek a better life, but what we are seeing is unhealthy acculturation and assimilation,” Sharma explained. “Some women come here healthier and they get unhealthier over time probably by adopting habits of the dominant culture that increase poor health outcomes.”

For example, immigrants may experience diet changes when they move to the US, as they assimilate to the culture and have access to different food or grocery sources. That decline in healthy diet, and overall healthy behavior, could explain why immigrants who have been in the US longer see a growing risk for preeclampsia.

Sharma also acknowledged the role of structural racism and implicit bias, two social factors some immigrants may experience differently than their US-born counterparts.

“While we didn’t specifically look at the impact of structural racism on health in this study, it may also play a role here,” she said. “Black women who were born outside the U.S. but immigrated to the country recently may be somewhat protected from the effects of discrimination because they tend to settle in immigrant-concentrated residential areas with increased social support.”

Overall, these findings support the notion that race in and of itself is not necessarily a health risk factor. Rather, they indicate that certain social determinants of health—access to care, structural racism, and neighborhood disadvantage—may in fact be the driving factors behind poor birthing outcomes. According to Sharma, Black people are more likely to experience those social determinants of health, playing out into a racial health disparity.

To begin to eliminate that racial health disparity, healthcare providers must rethink how they risk stratify pregnant people and develop patient education and social services programming to address those upstream factors.