From the Guidelines
Placental location other than previa can increase the risk of postpartum bleeding and atony, particularly in fundal and cornual implantation sites, and therefore requires active management of the third stage of labor with oxytocin and careful monitoring for excessive bleeding. The most common cause of early postpartum hemorrhage (PPH) is related to uterine atony or lack of effective uterine contraction after delivery, which is typically a clinical diagnosis in >75% of patients 1. Uterine atony is initially treated by uterine massage and uterotonic drugs such as oxytocin, and the majority of patients respond well to these treatments 1.
Key Considerations
- Placental implantation in the lower uterine segment (but not reaching the cervical os) may also increase bleeding risk due to the thinner myometrium in this region.
- Fundal and cornual regions have fewer muscle fibers and more connective tissue, potentially leading to less effective contractions in these areas after placental separation.
- Active management of the third stage of labor with oxytocin (10-40 units in 1L IV fluids or 10 units IM) is recommended for patients with higher-risk placental locations.
- Clinicians should maintain heightened vigilance during the immediate postpartum period for these patients, as early recognition and intervention for atony can significantly reduce morbidity from excessive blood loss.
Prophylactic Measures
- Careful monitoring for excessive bleeding
- Having additional uterotonics readily available (methylergonovine 0.2mg IM, misoprostol 800-1000mcg rectally, or carboprost 250mcg IM)
- Surgical procedures to control intraoperative and immediate hemorrhage such as uterine or ovarian artery ligation or uterine compression sutures may be utilized in the setting of cesarean section 1.
From the Research
Placental Location and Postpartum Bleeding Risk
- The provided studies do not directly address the relationship between placental location (other than previa) and the risk for postpartum bleeding and atony 2, 3.
- However, they do discuss the causes and management of uterine atony, which is a major contributor to postpartum hemorrhage.
- Uterine atony is identified as the underlying etiology in up to 80% of postpartum hemorrhage cases 3.
Uterine Atony Risk Factors
- While the studies do not specifically mention placental location as a risk factor, they do discuss other risk factors and prevention strategies for uterine atony 2, 3.
- The optimal prophylactic dose of oxytocin and alternative treatments such as carbetocin are discussed as ways to prevent uterine atony 3.
Management of Uterine Atony
- The studies review various treatments for uterine atony, including uterotonic agents, prostaglandin therapy, and newer supplementary medical therapies 2, 3.
- However, there is no direct mention of how placental location (other than previa) affects the management of uterine atony or postpartum bleeding.