A

Gross hematuria during labor in a woman with a previous lower-segment cesarean is classically an early warning of scar dehiscence/uterine rupture, often caused by simultaneous bladder injury as the scar gives way; case reports of VBAC cite hematuria as a presenting sign immediately preceding confirmed uterine rupture [Lee & Cass 1992, PMID 1538460; Ho et al. 2010, PMID 21145516].