Authors' response to the comment on "Antepartum hemorrhage from previous-cesarean-sectioned uterus as a potential sign of uterine artery pseudoaneurysm".

Thanks for the good comment by Matsubara et al. (2017) on our case of "Antepartum hemorrhage from previous-cesarean-sectioned uterus as a potential sign of uterine artery pseudoaneurysm" (Zhang et al., 2017), published in the Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology). In the comment, the authors clarified two possibilities of our scenario: the uterine artery pseudoaneurysm (UAP) could be newly formed in the present delivery as a result of vulnerability of uterine artery and/or its branches at the site of previous cesarean section (CS) scar to exogeneous stimuli during labor contractions; the other possibility is that previous CS caused UAP formation but remained unruptured, and UAP continued to be intrauterine, a hyper-dynamic state during labor causing UAP-sac rupture and resultant antepartum hemorrhage, as well as postpartum hemorrhage.