Nurse workforce diversity and reduced risk of severe adverse maternal outcomes.

Background: Racial and ethnic diversification of the physician and nurse workforce is recommended as a leverage point to address the impact of structural racism in maternal care, but empirical evidence supporting this recommendation is currently lacking.

Objective: This study aimed to assess the association between state-level registered nurse workforce racial and ethnic diversity and severe adverse maternal outcomes during childbirth.

Study Design: This population-based cross-sectional study analyzed 2017 US birth certificate data. Severe adverse maternal outcomes included eclampsia, blood transfusion, hysterectomy, or intensive care unit admission. Proportions of minoritized racial and ethnic registered nurses in each state were abstracted from the American Community Survey (5-year estimate, 2013-2017). This proportion was categorized into 3 terciles, with the first tercile corresponding to the lowest proportion and the third tercile corresponding to the highest proportion. Crude and adjusted odds ratios and 95% confidence intervals of severe adverse maternal outcomes associated with terciles of the state proportion of minoritized racial and ethnic nurses were estimated using logistic regression models.

Results: Of the 3,668,813 birth certificates studied, 29,174 recorded severe adverse maternal outcomes (79.5 per 10,000; 95% confidence interval, 78.6-80.4). The mean state proportion of minoritized racial and ethnic nurses was 22.1%, ranging from 3.3% in Maine to 68.2% in Hawaii. For White mothers, the incidence of severe adverse outcomes was 85.3 per 10,000 for those who gave births in states in the first tercile of the proportion of minoritized racial and ethnic nurses and 53.9 per 10,000 for those who gave birth in states in the third tercile (risk difference, -31.4 per 10,000; 95% confidence interval, -34.4 to -28.5). It corresponds to a 37% decreased risk of severe adverse maternal outcomes associated with giving birth in a state in the third tercile (crude odds ratio, 0.63; 95% confidence interval, 0.60-0.66). A decreased risk of severe adverse maternal outcomes was observed for Black mothers (crude odds ratio, 0.65; 95% confidence interval, 0.61-0.70), Hispanic mothers (crude odds ratio, 0.51; 95% confidence interval, 0.48-0.54), and Asian and Pacific Islander mothers (crude odds ratio, 0.65; 95% confidence interval, 0.58-0.72) but not for Native American mothers (crude odds ratio, 0.89; 95% confidence interval, 0.72-1.09) or mothers with >1 race (crude odds ratio, 1.44; 95% confidence interval, 0.72-1.09). After adjustment for patients and hospital characteristics, giving birth in states in the third tercile was associated with a reduced risk of severe adverse outcomes as follows: 32% for White mothers (adjusted odds ratio, 0.68; 95% confidence interval, 0.59-0.77), 20% for Black mothers (adjusted odds ratio, 0.80; 95% confidence interval, 0.65-0.99), 31% for Hispanic mothers (adjusted odds ratio, 0.69; 95% confidence interval, 0.58-0.82), and 50% for Asian and Pacific Islander mothers (adjusted odds ratio, 0.50; 95% confidence interval, 0.38-0.65). The associations of the proportion of minoritized racial and ethnic nurses with the risk of severe adverse maternal outcomes were not statistically significant for Native American mothers and more than 1 race mothers. Results were similar when blood transfusion was excluded from the outcome measure.

Conclusion: A diverse state registered nurse workforce was associated with a reduced risk of severe adverse maternal outcomes during childbirth.