Going the distance: Associations between adverse birth outcomes and obstetric provider distances for adolescent pregnancies in South Carolina.

PURPOSE

Distances to obstetric care providers are a persistent concern, especially for rural pregnant adolescents. Births to adolescents are disproportionately affected by adverse birth outcomes (ABOs), yet little is known regarding how driving distances may impact ABOs. This study examines the association between driving distances to obstetric providers and ABOs among adolescent mothers in South Carolina.

METHODS

This retrospective cross-sectional study derived ZIP Code-level birth statistics from mothers aged 10-19 in South Carolina using 2013-2017 statewide birth certificate data. ABOs included preterm birth and/or low birthweight. Provider distance was calculated between an obstetric provider's ZIP Code tabulated area (ZCTA) centroid and a maternal resident's ZCTA centroid. Descriptive statistics and weighted generalized linear regression were conducted.

RESULTS

Mean provider distances to obstetric providers were similar between urban (11.76 miles) and rural adolescent mothers (12.04 miles). An increase in provider distance, on average, was associated with a decrease in ABO rates (-0.79, p= .0038); however, rural-urban differences were found. Living in a rural ZCTA was associated with a decrease in ABOs (4.94%, p = .0043). Urban ZCTAs showed a U-shaped association with provider distance, with ABO rates decreasing until approximately 17 miles away from a provider and then increasing.

CONCLUSION

Rural adolescent mothers with greater distance to providers had lower ABO rates, while, in urban ZCTAs, provider distance over 17 miles was associated with higher ABO rates. Understanding what mitigates the effects of driving distance on ABOs in rural South Carolina would help inform future policy planning in underserved communities.