OBJECTIVE the main objective was to identify risk factors of relaparotomy for intra-abdominal hemorrhage (IAH) after cesarean delivery. The secondary objectives were to identify clinical warning signs associated with IAH: heart rate>120/min, systolic blood pressure<90 mmHg, scar bleeding, unconsciousness or abdominal pain with visual analog pain scale > 7 or use of category 3 analgesic medications, in the post-anesthesia care unit and in the post-partum unit. METHODS a case-control study (1:2 ratio), in two academic tertiary perinatal centers during 2008-2017. Postpartum laparotomies performed for another indication were excluded. The cases were women who underwent relaparotomy for IAH. A control group comprised women who had an uncomplicated cesarean delivery before and after each case. RESULTS 19,007 women had a cesarean delivery during the study period and among them 52 relaparotomies (0.27 %) for IAH were performed. 48 cases were compared to 96 controls. In multivariate analysis, the existence of a preeclampsia (aOR = 2.8, 95 % IC 1.1-7.4), urgent cesarean (aOR = 3.2, 95 % IC 1.1-9.6), surgical difficulties during initial cesarean (aOR = 9.0, 95 % IC 2.8-23.8), and estimated blood loss > 500 mL during initial cesarean (aOR = 7.4, 95 % IC 2.4-22.5) were independently associated with IAH. Tachycardia > 120/min was the most discriminating factor associated with the occurrence of relaparotomy for IAH (84 %). In the absence of tachycardia, hypotension < 90 mmHg was the second most discriminant factor for IAH (73 %). CONCLUSIONS preeclampsia, urgent cesarean, surgical difficulties and blood loss > 500 mL during initial cesarean were independently associated with an increased risk of relaparotomy for IAH. Tachycardia and/or hypotension were discriminant-warning signs for severe IAH.