(151) Association Between Rural-to-Urban Obstetric Transport and Severe Maternal Morbidity and Neonatal Complications

Objective: To compare the frequency of severe maternal morbidity (SMM) between obstetric transports from rural-to-urban counties (RTU) versus urban-to-urban (UTU) counties.

Study Design: Retrospective cohort study of pregnant individuals undergoing transport for delivery for maternal medical or fetal indications using National Vital Statistics System birth records from 2016-2021. Inclusion criteria were all individuals who underwent transport with available county level data. The primary exposure was maternal residence in a rural county (< 99 individuals per square mile). The primary outcome was SMM (ICU admission, uterine rupture, hysterectomy, and blood transfusion). The secondary outcome was a composite of neonatal complications. Maternal demographic, obstetric, and medical factors were assessed as potential covariates. We performed univariate and bivariate analyses using Chi-squared and Wilcoxon tests as appropriate. A multivariable generalized linear model was used to assess the association between rurality and outcomes.

Results: 117,050 obstetric transports occurred between 2016-2021 (0.52% of all births). Among people undergoing RTU transports, SMM was lower than UTU transports (3.4% versus 3.7%, p=0.012). Neonatal complications were higher among RTU versus UTU transports (71.3% versus 63.6%, p=< 0.001). After adjusting for covariates, people undergoing RTU transports had 12% lower odds of SMM than UTU transports [aOR 0.88, 95% CI (0.81-0.95, p=0.001)]. However, neonates born after RTU transports had 7% higher odds of neonatal morbidity [aOR 1.07, 95% CI (1.03-1.11, p< 0.001)] (Figure). 

Conclusion: Pregnant people undergoing UTU obstetric transportation experience higher rates of SMM than RTU transports, which may reflect differences in threshold to transfer based on hospital capabilities. Neonatal complications are higher amongst RTU transports compared to UTU transports, indicating that RTU transports may be more likely to involve complications that affect neonatal safety.