Preterm birth (PTB) is not homogeneously distributed among populations. Risk factors can accumulate in discrete locations. We sought to investigate the geographical relationships between PTB and sociodemographic factors as denoted by ZIP code.METHODS:
We conducted an ecological analysis of data from 2012 to 2014 in each Rochester ZIP code using vital statistics, hospital records and the American Community Survey. Pearson correlation coefficients (r) assessed the relationship between PTB rates and sociodemographic variables by ZIP code. Geographic information system (GIS) mapping explored the spatial relationships of PTB rates.RESULTS:
17,876 deliveries occurred with a PTB rate of 11.3%. The PTB rate ranged from 6.8% to 15.6% across 22 ZIP codes. GIS mapping demonstrated clustering of ZIP codes with the highest PTB rates in the urban center which overlapped with high levels of poverty and crime. Increased PTB rates significantly correlated with ZIP codes containing the largest percentage of minorities (r=0.836, P<0.001). PTB rates positively correlated with inadequate prenatal care (r=0.864, P<0.001), unmarried status (r=0.857, P<.001), state-funded insurance (r=0.848, P<0.001), poverty (r=0.855, P<0.001) and teen pregnancy rates (r=0.709, P<0.001) by ZIP code. Areas with the highest PTB rates had the lowest number of obstetric providers (r = -0.385, p=0.077).CONCLUSION:
Rochester ZIP codes have a high correlation between PTB rate and sociodemographic factors, highlighting the abundance of risk factors that concentrate in geographic areas. The high risk areas seem to lack obstetric care providers. Policies and interventions should target these ZIP codes in order to improve PTB rates and access to care.