Ethnic density effects on birth outcomes and maternal smoking during pregnancy in the US linked birth and infant death data set.
OBJECTIVE
We investigated whether mothers from ethnic minority groups have better pregnancy outcomes when they live in counties with higher densities of people from the same ethnic group-despite such areas tending to be more socioeconomically deprived.


METHODS
In a population-based US study, we used multilevel logistic regression analysis to test whether same-ethnic density was associated with maternal smoking in pregnancy, low birthweight, preterm delivery, and infant mortality among 581 151 Black and 763 201 Hispanic mothers and their infants, with adjustment for maternal and area-level characteristics.


RESULTS
Higher levels of same-ethnic density were associated with reduced odds of infant mortality among Hispanic mothers, and reduced odds of smoking during pregnancy for US-born Hispanic and Black mothers. For Black mothers, moderate levels of same-ethnic density were associated with increased risk of low birthweight and preterm delivery; high levels of same ethnic density had no additional effect.


CONCLUSIONS
Our results suggest that for Hispanic mothers, in contrast to Black mothers, the advantages of shared culture, social networks, and social capital protect maternal and infant health.
Shaw
Richard J
RJ
Department of Health Sciences, University of York, Heslington, York, YO10 5DD, UK. rjs515@york.ac.uk
Pickett
Kate E
KE
Wilkinson
Richard G
RG
D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D007226:Infant Mortality / Q000208:ethnology; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D016015:Logistic Models; D008875:Middle Aged; D008913:Minority Groups / Q000706:statistics & numerical data*; D010298:Parity; D011156:Population Density; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology* / Q000208:ethnology; D047928:Premature Birth / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology*; D012959:Socioeconomic Factors; D014481:United States / Q000453:epidemiology / Q000208:ethnology; D055815:Young Adult