Social disadvantage and the black-white disparity in spontaneous preterm delivery among California births

PLoS One. 2017 Aug 11;12(8):e0182862. doi: 10.1371/journal.pone.0182862. eCollection 2017.


We examined the contribution of social disadvantage to the black-white disparity in preterm birth. Analyses included linked vital and hospital discharge records from 127,358 black and 615,721 white singleton California births from 2007-11. Odds ratios (OR) were estimated by 4 logistic regression models for 2 outcomes: early (<32 wks) and moderate (32-36 wks) spontaneous preterm birth (ePTB, mPTB), stratified by 2 race-ethnicity groups (blacks and whites). We then conducted a potential impact analysis. The OR for less than high school education (vs. college degree) was 1.8 (95% confidence interval 1.6, 2.1) for ePTB among whites but smaller for the other 3 outcome groups (ORs 1.3-1.4). For all 4 groups, higher census tract poverty was associated with increased odds (ORs 1.03-1.05 per 9% change in poverty). Associations were less noteworthy for the other variables (payer, and tract percent black and Gini index of income inequality). Setting 3 factors (education, poverty, payer) to 'favorable' values was associated with lower predicted probability of ePTB (25% lower among blacks, 31% among whites) but a 9% higher disparity, compared to probabilities based on observed values; for mPTB, respective percentages were 28% and 13% lower probability, and 17% lower disparity. Results suggest that social determinants contribute to preterm delivery and its disparities, and that future studies should focus on ePTB and more specific factors related to social circumstances.

MeSH terms

  • Adult
  • African Americans
  • California / epidemiology
  • European Continental Ancestry Group
  • Female
  • Humans
  • Infant, Newborn
  • Male
  • Odds Ratio
  • Poverty / ethnology
  • Poverty / statistics & numerical data*
  • Pregnancy
  • Premature Birth / economics
  • Premature Birth / epidemiology*
  • Premature Birth / ethnology*
  • Risk Factors
  • Socioeconomic Factors*