Social Determinants of Health and Risk of Stillbirth in the United States

Objective Our aim was to evaluate the impact of social determinants of health (SDoH) risk factors on stillbirth among pregnancy-related hospitalizations in the United States. Study Design We conducted a cross-sectional analysis of delivery-related hospital discharges using annualized data (2016-2017) from the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample. The International Classification of Diseases, 10th Revision ICD-10-CM codes were used to select women with singleton stillbirth. Z-codes were utilized to identify SDoH risk factors and their subtypes. The association between SDoH risk factors and stillbirth was assessed using survey logistic regression models. Results We analyzed 8,148,646 hospitalizations, out of which 91,140 were related to stillbirth hospitalizations, yielding a stillbirth incidence of 1.1%. An increased incidence was observed for non-Hispanic (NH) Blacks (1.7%) when compared with NH Whites (1.0%). The incidence of stillbirth was greater in hospitalizations associated with SDoH risk factors compared with those without risk factors [2.0% vs. 1.1% ( p <0.001)]. Among patients with SDoH risk factors, the rate of stillbirth was highest in those designated as NH other (3.0%). Mothers that presented with SDoH risk factors had a 60% greater risk of stillbirth compared with those without (odds ratio [OR] = 1.61 [95% confidence interval (CI) = 1.33-1.95], p < 0.001). The SDoH issues that showed the most significant risk for stillbirth were: occupational risk (OR = 7.05 [95% CI: 3.54-9.58], p < 0.001), upbringing (OR = 1.87 [95% CI: 1.23-2.82], p < 0.001), and primary support group and family (OR = 5.45 [95% 3.84-7.76], p < 0.001). Conclusion We found pregnancies bearing SDoH risk factors to be associated with a 60% elevated risk for stillbirth. Future studies should target a variety of risk reduction strategies aimed at modifiable SDoH risk factors that can be widely implemented at both the population health level as well as in the direct clinical setting.