A retrospective review of 125 pregnant women with blunt injuries admitted to a level I trauma center over a 35-month period was performed. The usefulness of three diagnostic tests, fetal ultrasound (US), external fetal monitoring (EFM), and Kleihauer-Betke (KB) tests in detecting fetal or pregnancy-associated complications was evaluated. The majority of women (77.6%) were involved in motor vehicle crashes and the mean Injury Severity Score was low (4.7). The most common complications were premature uterine contractions (67%) and abruptio placentae (11%). When used together, EFM and US identified all complications. Moreover, all complications were manifest within 6 hours of admission. The KB tests had a sensitivity of 56%, a specificity of 71%, and an accuracy of 27%. We conclude that EFM and US are more useful in detecting fetal or pregnancy-associated complications after blunt injury. Monitoring can be limited to 6 hours if previous monitoring is normal. The KB test is of little use in the setting of acute trauma.