Trauma in pregnancy and severe adverse perinatal outcomes

Trauma, including accidental and violent trauma, is a rare but severe complication of pregnancy. The incidence of adverse perinatal outcomes in pregnancies affected by traumatic injury has not been well-studied.

We sought to characterize the association between traumatic injury during pregnancy and severe adverse perinatal outcomes in a large population.

We performed a retrospective cohort study of California Birth Registry data from 2007 to 2011. ICD-9 diagnosis and procedure codes were used to categorize patients into trauma and non-trauma cohorts and to assess the prevalence of severe adverse fetal and neonatal outcomes. Chi-square tests were used to characterize maternal demographics and perform univariate analyses, and logistic regression was used to control for potential confounders.

Of 2,406,605 singleton nonanomalous pregnancies, 1262 (0.05%) experienced trauma prior to delivery. The rate of composite perinatal outcomes was higher in pregnancies with trauma compared to those without (3.1 versus 0.87%, p < .001). Trauma was associated with higher occurrences of preterm birth <37 weeks, preterm birth <32 weeks, very low birth weight and neonatal death. Fetal demise at any gestational age was more common among trauma patients (1.9 versus 0.53%, p < .001), though this difference was not statistically significant among term fetuses (0.28 versus 0.14%, p = .21). A difference in composite adverse perinatal outcomes was seen even after controlling for important maternal characteristics (aOR 3.2, 95% CI). Trauma patients with severe morbidity compared to those without had higher rates of preterm birth <37 weeks, preterm birth <32 weeks, and composite severe perinatal outcomes.

Trauma in pregnant women is associated with an increased risk of severe adverse perinatal outcomes, including fetal and neonatal demise. Prevalence of fetal demise is not different between trauma and non-trauma mothers when looking at term fetuses only, suggesting that the greatest risk of fetal demise in the setting of trauma occurs in the preterm period. These data can be used to counsel patients and to inform more detailed research into the mechanisms of trauma in pregnancy outcomes.