A new nationwide study has found that higher minimum wages are linked to lower rates of dangerous pregnancy-related hypertension, highlighting the potential impact of economic policy on maternal health.
The research, published in the American Journal of Preventive Medicine, analyzed state-level data from all 50 U.S. states and Washington, DC, spanning from 1992 to 2019. The study focused on whether increases in minimum wage levels were associated with changes in the incidence of maternal hypertensive disorders and other nonfatal obstetric conditions.
Nearly one in twelve pregnant women in the United States develops a hypertensive disorder during pregnancy. These conditions—such as gestational hypertension, preeclampsia, and eclampsia—are leading contributors to illness and death among pregnant women. The rate of these disorders has doubled over the past decade and disproportionately affects women from socially and economically disadvantaged backgrounds, especially racial and ethnic minorities.
Researchers used annual state-level data covering 1,428 state-year observations without missing data. Information about nonfatal maternal disorders was sourced from the Global Burden of Disease (GBD) study for consistency across states and time periods. Minimum wage information came from the University of Kentucky Center for Poverty Research and was linked by state and year to health outcomes. Additional variables included economic indicators and demographic factors from sources such as the Kaiser Family Foundation, Centers for Disease Control and Prevention, and Integrated Public Use Microdata Series.
Minimum wage was examined both as a continuous measure and as a binary indicator showing whether a state's minimum wage increased by at least one dollar compared to the previous year. The analysis looked at several categories of nonfatal maternal disorders including hypertensive disorders, pregnancy loss, labor complications, hemorrhage, and infections.
Regression models were used within a generalized difference-in-differences event study framework that adjusted for various economic trends and demographic characteristics. This approach aimed to strengthen causal interpretation despite being an observational study.
The results showed that states with minimum wages above the federal level had lower average rates of maternal hypertensive disorders—372 cases per 100,000 women compared to 431 cases per 100,000 in states at the federal minimum wage level. Incidence rates for obstructed labor and sepsis were also lower where minimum wages exceeded federal requirements.
In contrast, higher rates of abortion or miscarriage were observed in states with higher minimum wages; however, researchers did not interpret this finding as causal.
When examining years following a one-dollar or greater increase in minimum wage policy within a state (61 instances during the period studied), researchers found that such increases were associated with significantly fewer cases of maternal hypertensive disorders—specifically 64.8 fewer cases per 100,000 women over four years after each policy change.
There was also an association between higher minimum wages and reduced postpartum hemorrhage (27.4 fewer cases per 100,000 women), though these findings were less consistent across different model specifications.
No significant associations emerged between increased minimum wage policies and other categories of obstetric disorders after adjustments for confounding factors.
According to the authors: "This study showed that state minimum wage increases of one dollar or more were associated with meaningful reductions in maternal hypertensive disorders at the population level." They added: "The strongest associations appeared two to four years after policy changes," suggesting benefits may stem from improved health before pregnancy rather than during it.
They concluded: "Overall, the results suggest that minimum wage policies may improve maternal health by addressing social and economic determinants." However they cautioned: "Individual-level data are needed to confirm mechanisms and subgroup effects," which could have implications for reducing pregnancy-related morbidity and mortality nationwide.
