Original Research Original Research|Articles in Press, 100915

Accuracy and utilization patterns of intra-abdominal imaging for major trauma in pregnancy



      Imaging protocols for maternal major trauma during pregnancy are not standardized, and it is uncertain whether focused assessment with sonography for trauma (FAST) or computed tomography of the abdomen/pelvis (CTAP) is preferred for detecting intra-abdominal hemorrhage.


      To estimate the accuracy of the FAST exam compared to CTAP, validate imaging accuracy with clinical outcomes, and describe clinical factors associated with each imaging mode.

      Study Design

      A retrospective cohort study of pregnant patients evaluated for major trauma at one of two Level 1 trauma centers between 2003 and 2019. We identified 4 imaging groups: no intra-abdominal imaging, FAST only, CTAP only, and both FAST and CTAP. The primary outcome was a composite maternal severe adverse pregnancy outcome, including death and intensive care unit admission. We estimated sensitivity, specificity, and positive and negative predictive values of FAST for hemorrhage with reference CTAP. We performed ANOVA and chi-squared tests to compare clinical factors and outcomes across imaging groups. Multinomial logistic regression was used to estimate associations between selected imaging mode and clinical factors.


      Of 119 pregnant trauma patients, 31 (26.1%) experienced a maternal severe adverse pregnancy outcome. Intra-abdominal imaging modes included none in 37.0%, FAST only in 21.0%, CTAP only in 25.2%, and both modes in 16.8%. With CTAP as the reference, FAST exam had sensitivity, specificity, positive predictive value, and negative predictive value of 11%, 91%, 50%, and 55%, respectively. One patient had a maternal severe adverse pregnancy outcome with a positive FAST and negative CTAP and two patients with a positive CTAP did not have an adverse outcome. Use of CTAP with or without FAST exam was associated with a higher injury severity score, lower systolic blood pressure nadir, higher motor vehicle collision speed, and higher rates of hypotension, tachycardia, bone fracture, maternal severe adverse pregnancy outcome and fetal demise. The association of CTAP use with higher injury severity score, tachycardia, and lower systolic blood pressure nadir persisted in multivariable analysis. With each 1-point increase in the ISS, there was an 11% more likelihood of using CTAP over FAST exam for intra-abdominal imaging.


      The sensitivity of FAST in detecting intra-abdominal hemorrhage in pregnant trauma patients is poor, and CTAP has a low false-negative rate. Providers appear to prefer CTAP to FAST in patients with the most severe trauma. CTAP with or without FAST is more accurate than FAST alone.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Obstetrics & Gynecology MFM
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect