480 - The impact of rurality on very low birth weight infant morbidity and mortality

Poster Number: 480
Publication Number: 480.129

Devlynne S. Ondusko, Oregon Health & Science University School of Medicine, Portland, OR, United States; Jessica Liu, Stanford University School of Medicine, Palo Alto, CA, United States; Brigit Hatch, Oregon Health & Science University School of Medicine, Portland, OR, United States; Jochen Profit, Stanford University, Palo Alto, CA, United States; Emily H. Carter, Doernbecher Children's Hospital at Oregon Health & Science University, Portland, OR, United States

Background: People living in rural and frontier areas experience higher morbidity and mortality in many areas of health care. Whether rurality affects care and outcomes for very low birthweight (VLBW; < 1500g) infants is not well understood.

Objective: This study compares prenatal factors, care patterns, and health outcomes between VLBW infants born to mothers living in rural versus urban zip codes in California.

Design/Methods: We used data from the California Perinatal Quality Care Collaborative (CPQCC) registry to conduct a population-based retrospective cohort study of VLBW infants born between January 1, 2011, and December 31, 2018. This descriptive analysis examined associations between the degree of maternal residential rurality and maternal, infant, hospital, and community/county level characteristics based on Rural Urban Commuting Area (RUCA) codes. The associations between all factors and maternal RUCA codes were stratified and compared using Chi-squared and ANOVA tests. The primary outcome was survival without major morbidities (SWMM). Odds ratios of SWMM were calculated for each variable adjusting for maternal age and race.

Results: Our study included 38,614 VLBW infants. Of those, 36,936 were born to mothers residing in an urban area, 1,113 in a large rural area, and 561 within a small rural or isolated area. Mothers of VLBW infants who live in large rural and small rural/isolated areas were more likely to be younger; publicly insured; have education limited to high school; smoke during pregnancy; and have delayed, no, or unknown prenatal care. Birth weight, gestational age, and infant sex were similar across geographic groups. SWMM exhibited a significant and progressive rural disadvantage. The covariates that were significant for VLBW infants born to mothers from large rural and small rural/isolated areas were analyzed for association with SWMM in a model adjusting for maternal age and race/ethnicity. The covariates that were associated with lower odds of SWMM included precipitous labor (p < 0.001), outborn delivery (p < 0.001), unknown prenatal care (p=0.02), lack of hypertension (p=0.001), no delayed cord clamping (p < 0.001), lower APGAR at 1 and 5 minutes (p < 0.001), lower rates of human milk feeds at discharge (p < 0.001), and residing over 40 miles from the birth hospital (p < 0.001).Conclusion(s): VLBW infant SWMM decreased with increasing rurality. This study highlights various risk and protective factors and may inform future intervention to improve maternal and newborn health through health policy intervention.
CVCV Ondusko.pdf