The Effect of Hospital Trauma Level on Outcomes for Injured Pregnant Women and their Neonates in Washington State, 1995 to 2012
Trauma occurs in 6 to 7% of all pregnancies, however, no studies have evaluated the effect of the trauma certification level of the hospital as it relates to maternal and neonatal outcomes for injured pregnant women who are hospitalized in a trauma center.
We performed a population-based, retrospective cohort study evaluating the association between trauma designation Levels 1 and 2 (Level 1-2) and Levels 3 and 4 (Level 3-4) and maternal and neonatal birth outcomes. Study subjects were pregnant women hospitalized for injury identified by linking Washington State birth and fetal death certificate data and the Washington State Comprehensive Hospital Abstract Recording System (CHARS). As the start date of the study was chosen to correspond with the initiation of the trauma hospital designation system in Washington State, this study evaluated injured pregnant women from 1995 through 2012. Injury was identified using International Classification of Diseases, Ninth Revision (ICD-9) injury diagnosis and external causation (E) codes. Specific types of injuries and mechanisms of injury were abstracted from the database. The association between higher-level trauma hospital designation and risk of adverse maternal and neonatal birth outcomes was analyzed using logistic regression to estimate odds ratios and 95% confidence intervals (CI), adjusting for Injury Severity Score.
Following exclusions, 2,492 injured pregnant women hospitalized in a trauma center were identified for analysis. With few exceptions, maternal and neonatal birth outcomes showed no association with trauma hospital level designation. Women treated at trauma Level 1-2 hospitals had an adjusted odds ratio of preterm labor of 1.43 (95% CI: 1.15-1.79, p < 0.01). Neonates of women treated at trauma Level 1-2 hospitals had an adjusted odds of meconium at delivery of 1.66 (95% CI: 1.05-2.61, p < 0.01). Neonates of women with severe injuries, ISS > 9, treated at trauma Level 1-2 hospitals had an adjusted odds of low birth weight, < 2, 500 grams, of 2.52 (95% CI: 1.12-5.64, p < 0.01). All other maternal and neonatal birth outcomes showed no association with trauma hospital level designation.
The majority of maternal and neonatal outcomes had no association with hospitalization at a Level 1-2 trauma center compared to a Level 3-4 trauma center. This study can inform state trauma systems, guide allocation of trauma resources and pre-hospital patient care.