Influence of Socioeconomic Status on Adverse Outcomes in Pregnancy [15C

Abstract

INTRODUCTION: Lower socioeconomic status (SES) has been associated with adverse pregnancy outcomes. We determined whether ZIP-code level-based SES indicator was associated with adverse pregnancy outcomes. METHODS: Retrospective study of OHSU births from 2009–2014 compared adverse pregnancy outcomes among women living in 88 Portland metro-area ZIP-codes stratified into 3 median household income groups: Low (below 10th percentile), medium (10th-90th percentile), and high (above 90th percentile) socioeconomic status (SES). Perinatal outcomes were compared by univariate analysis; multivariable logistical regression determined strength of association of low and high SES with adverse outcomes (medium SES=reference group), adjusting for significant variables. RESULTS: Of 8,118 deliveries included, 1,654 (20%) were in low SES, 5,856 (72%) were in medium SES, and 608 (8%) were in high SES. Women in low SES were more likely to be younger, have higher BMI and tobacco use, and have less private insurance. Lower SES was associated with higher rates of preeclampsia (PEC) (9.02% vs 7.48% vs 5.93%, P<.028) and small for gestational age (SGA) (10.7% vs 9.34% v 6.61%, P<.012), and lower birth weights (mean 3,280 g vs 3,340 g vs 3,592 g, P<.001). High SES was associated with lower gestational diabetes mellitus (GDM) rates (10.8% vs 11.0% vs 7.58%, P<.036), even after adjusting for confounders (aRR high SES 0.710, 95% CI 0.507–0.995). CONCLUSION: In the Portland metro-area, low SES is associated with higher rates of PEC and SGA. High SES is associated with lower rates of GDM. ZIP-code level SES indicator detects perinatal outcome differences and may be useful for identifying healthcare disparities.