Placenta previa, a medical condition characterized by a low attachment of the placenta over the cervical opening, can increase the risk of hysterectomy and excessive blood loss during C-section delivery. In a study of 33 patients with placenta previa, increta or accreta, researchers tested aortic balloon occlusion as a means of reducing the number of hysterectomies and improving overall surgical outcome.

Aortic balloon occlusion was performed on 15 patients who agreed to the procedure. The remaining 18 patients in the study refused the balloon and were placed in the control group. Before the schedule C-section, the balloon was used to expand the abdominal aorta. There were no reported complications associated with aortic expansion.
When surgical outcomes were compared, women in the balloon group suffered fewer hysterectomies and less blood loss than the control group. The control group spent more time in the hospital with more cases of intensive care than the group participating in aortic expansion.

Test results suggest aortic expansion reduces the risk of blood loss, extended hospital stay and hysterectomy when performed before a scheduled C-section delivery in patients with placenta previa.

Source: Panici PB, Anceschi M, Borgia ML, Bresadola L, Masselli G, Parasassi T, Perrone G; Fetal Maternal Risk Group, Brunelli R. Intraoperative aorta balloon occlusion: fertility preservation in patients with placenta previa accreta/increta. J Matern Fetal Neonatal Med. 2012 Sep 20.

http://www.ncbi.nlm.nih.gov/pubmed/22992070