BACKGROUND: Most pregnant trauma patients (PTPs) present after motor vehicle collision (MVC). The national rate and risk factors for emergency cesarean section (ECS) during the index hospitalization for pregnant trauma patients (PTPs) are unknown. We sought to investigate the national rate of ECS in PTPs presenting after MVC, hypothesizing a higher risk of ECS among those with severe injuries or elevated shock index (SI). METHODS: The 2020-2021 TQIP was queried for PTPs presenting after MVC. PTPs that underwent ECS were compared to patients that did not undergo ECS. Elevated SI was defined as ≥1. Severe injury was defined by abbreviated injury scale grade ≥3. Bivariate and multivariable logistic regression analyses were performed. RESULTS: From 1183 PTPs, 95 (8.0 %) underwent ECS. The median time to ECS was 115 min. The ECS group had higher rates of lung (27.4 % vs. 12.2 %, p < 0.001) injury, spleen (18.9 % vs. 5.5 %, p < 0.001) injury, and elevated SI (22.1 % vs. 9.8 %, p < 0.001). ECS patients had higher rates of complication (9.5 % vs. 2.1 %, p < 0.001) and death (4.2 % vs. 1.1 %, p = 0.012). Independently associated risk factors for ECS included severe head (OR 2.65, CI 1.14-6.17, p = 0.023) or abdominal (OR 2.07, CI 1.08-3.97, p = 0.028) injuries and elevated SI (OR 2.17 CI 1.25-3.79, p = 0.006). CONCLUSION: The national rate of ECS among PTPs presenting after MVC is 8 % with most occurring within the first 2 hours of arrival. Severe head and abdominal injuries as well as elevated SI are risk factors for ECS.