So far, massive hemorrhage caused by PA during delivery is still a big challenge for obstetricians. In patients with PA, if the placenta does not completely separate from the uterus during delivery, massive obstetric hemorrhage will follow, leading to DIC and to a vicious circle of bleeding. When conservative treatments fail, traditional measures for massive obstetric hemorrhage include uterine artery ligation, internal iliac artery ligation, or even emergent hysterectomy. In the last 30–40 years, a new vascular interventional technique for treatment of obstetric hemorrhage has emerged. Pelvic arterial embolization and temporary occlusion of internal iliac arteries seem to be safe and effective for massive obstetric hemorrhage [
25]. However, studies have yielded conflicting results. Some studies showed these treatments could reduce blood loss, others showed no benefits, and some even showed significant complications [
26,
27].
The internal iliac artery is the main blood supply to the pelvic cavity. The uterine artery usually arises from the anterior division of the internal iliac artery, which is the main supply to the uterus. However, there are several other vascular territories that provide a rich collateral supply to the uterus, such as the ovarian artery, which arises from the abdominal aorta below the renal artery [
28‐
30]. So, theoretically, the abdominal aorta should be an ideal alternative site proposed for temporary occlusion, which may greatly diminish the collateral supply. Intra-aortic balloon occlusion (IABO) is not a new vascular interventional technique for controlling massive hemorrhage. An intraluminal aortic occlusion technique for controlling massive intra-abdominal hemorrhage was first reported by Edwards et al. in 1953 [
31]. The endovascular balloon occlusion technique has been widely used in various types of major bleeding since Edwards’ report. The endovascular balloon occlusion technique has been successfully used in, e.g., trauma, aneurysm, artery dissection, and tumors, etc. [
32‐
34]. For different regions of the aortic blood supply, Stannard et al. described in detail how different types of aortal occlusion, from the chest, to the abdominal cavity, to the pelvic cavity, can be chosen to reduce bleeding [
35]. Paull et al. first introduced the abdominal aortic balloon occlusion (AABO) technology into clinical practice in the obstetrics field to control intraoperative hemorrhage [
21]. Up to now, less than ten studies, with small sample sizes, using the AABO technology have been reported [
36‐
40]. Although most of them showed positive results, all these studies were almost retrospective studies. Current evidence is insufficient to recommend for or against routinely using the AABO technology to control intraoperative hemorrhage in patients with PA. Therefore, we hope to carry out this prospective RCT study to confirm the effectiveness of the AABO technology in patients with PA.