Major trauma in pregnancy: prediction of maternal and perinatal adverse outcomes

Trauma, largely the consequence of motor vehicle crashes, is the leading cause of pregnancy-associated maternal mortality. Prediction of adverse outcomes has been difficult in pregnancy given the infrequent occurrence of traumatic events and anatomic considerations unique to pregnancy. The injury severity score, an anatomic scoring system with weighting dependent on severity and anatomic region of injury, is used in the prediction of adverse outcomes in the nonpregnant population but has yet to be validated in pregnancy.

This study aimed to estimate the associations between risk factors and adverse pregnancy outcomes after major trauma in pregnancy and to develop a clinical prediction model for adverse maternal and perinatal outcomes.

This was a retrospective analysis of a cohort of pregnant patients who sustained major trauma and who were admitted to 1 of 2 level 1 trauma centers. Three composite adverse pregnancy outcomes were evaluated, namely adverse maternal outcomes and short- and long-term adverse perinatal outcomes, defined as outcomes occurring within the first 72 hours of the traumatic event or encompassing the entire pregnancy. Bivariate analyses were performed to estimate the associations between clinical or trauma-related variables and adverse pregnancy outcomes. Multivariable logistic regression analyses were performed to predict each adverse pregnancy outcome. The predictive performance of each model was estimated using receiver operating characteristic curve analyses.

A total of 119 pregnant trauma patients were included, 26.1% of whom met the severe adverse maternal pregnancy outcome criteria, 29.4% of whom met the severe short-term adverse perinatal pregnancy outcome definition, and 51.3% of whom met the severe long-term adverse perinatal pregnancy outcome definition. Injury severity score and gestational age were associated with the composite short-term adverse perinatal pregnancy outcome with an adjusted odds ratio of 1.20 (95% confidence interval, 1.11-1.30). The injury severity score was solely predictive of the adverse maternal and long-term adverse perinatal pregnancy outcomes with odds ratios of 1.65 (95% confidence interval, 1.31-2.09) and 1.14 (95% confidence interval, 1.07-1.23), respectively. An injury severity score ≥8 was the best cutoff for predicting adverse maternal outcomes with 96.8% sensitivity and 92.0% specificity (area under the receiver operating characteristic curve, 0.990±0.006). An injury severity score ≥3 was the best cutoff for the short-term adverse perinatal outcomes, which correlates with a 68.6% sensitivity and 65.1% specificity (area under the receiver operating characteristic curve, 0.755±0.055). An injury severity score ≥2 was the best cutoff for the long-term adverse perinatal outcomes, yielding a 68.3% sensitivity and 72.4% specificity (area under the receiver operating characteristic curve, 0.763±0.042).

For pregnant trauma patients, an injury severity score of ≥8 was predictive of severe adverse maternal outcomes. Minor trauma in pregnancy, defined in this study as an injury severity score <2, was not associated with maternal or perinatal morbidity or mortality. These data can guide management decisions for pregnant patients who present after trauma.