Marginal Sinus and Bleeding in Women with a Low-Positioned Placenta: A Narrative Synthesis Systematic Review

Among the five studies examining the relationship between marginal sinus and antepartum bleeding, a significant association was reported in four, while one found no such link. The only two studies examining the relationship between marginal sinus and intrapartum hemorrhage reported no association. Additionally, one of these studies identified lower rates of postpartum bleeding in women with normally located placental tissue and a marginal sinus reaching the internal os, compared with women with low-positioned placental tissue. The risk of bleeding in women with a low-positioned placenta and marginal sinus is still poorly evaluated. The evidence from the included studies lacked consistency and conclusive findings, highlighting the need for further research to elucidate this association and inform clinical management effectively. Additionally, studies failed to address the significance of marginal sinus in diagnosing and managing low-positioned placenta.