Objective: To assess whether positive flow cytometry quantification of fetal red blood cells is associated with adverse outcomes in cases of mild trauma during pregnancy. Design: A retrospective computerized database cohort. Population: Pregnant women with viable gestation involved in trauma who underwent flow cytometry. Flow cytometry was considered positive (≥0.03/≥30 ml). Methods: A univariate analysis was followed by a multivariate analysis. Main outcome measures: Composite adverse maternal and neonatal outcome was defined as one or more of the following: intrauterine fetal death, placental abruption, pre-term birth < 37 weeks of gestation, immediate premature rupture of the membranes, and immediate delivery following trauma. Results: During the study 1023 women met inclusion and exclusion criteria. Among the cohort, 119 women (11.6%) had positive flow cytometry (≥0.03/≥30 ml) with median result of 0.03 [0.03-0.04], while 904 women (88.4%) had negative flow cytometry test result (≤0.03/≤30 ml) with median result of 0.01 [0.01-0.02]. Composite adverse outcome occurred in 8% of the women, with no difference in the groups with vs. without positive flow cytometry (4.2% vs. 8.5%; p=0.1). Positive flow cytometry was not associated with any adverse maternal or neonatal outcome. This was confirmed on a multivariate analysis. Conclusions: Flow cytometry result is not related to adverse maternal and fetal/neonatal outcome of women involved in minor trauma during pregnancy. We suggest that flow cytometry should not be routinely assessed in pregnant women involved in minor trauma.