From the Guidelines
Expectant management of placenta previa should be considered only for carefully selected cases after detailed counseling about the risks, uncertain benefits, and efficacy, and should be considered investigational, as stated in the American Journal of Obstetrics and Gynecology 1. When considering expectant management, it is crucial to weigh the risks and benefits, taking into account the potential for significant maternal morbidity and mortality.
- The management approach should prioritize minimizing the risk of hemorrhage and optimizing fetal outcomes.
- Hospitalization until delivery is often recommended for patients with active bleeding, while those with stable, asymptomatic previa may be managed as outpatients with modified bed rest and pelvic rest.
- Corticosteroids, such as betamethasone, may be administered to accelerate fetal lung maturity, and tocolytics like nifedipine may be used to manage preterm contractions.
- Regular monitoring, including non-stress tests and ultrasound assessments, is essential to evaluate placental location, fetal growth, and cervical length.
- Patients should maintain close proximity to a hospital with blood products readily available, and iron supplementation may be recommended to prevent or treat anemia.
- Delivery timing depends on placental location and previous bleeding episodes, with planned cesarean delivery typically scheduled at 36-37 weeks for complete previa and 36-39 weeks for marginal previa, as supported by the American Journal of Obstetrics and Gynecology 1. It is essential to note that the degree of success with expectant management correlates with the degree of placental attachment abnormality, and severe adverse complications are more common in patients with placenta percreta, highlighting the need for individualized management and careful consideration of the risks and benefits.
From the Research
Expectant Management of Placenta Previa
- The expectant management of placenta previa involves careful monitoring and treatment to prevent preterm delivery and hemorrhage, with the goal of achieving delivery at 37 weeks' gestation with mature fetal lung function 2.
- A study published in 1984 reported the outcomes of 95 expectantly managed cases of placenta previa, with 86% of infants born weighing less than 2500 gm being managed expectantly, and a perinatal mortality rate of 4.2% 2.
- Another study published in 1996 compared inpatient and outpatient expectant management of symptomatic placenta previa, finding no significant differences in outcomes between the two groups, but a significant reduction in maternal hospital days and costs with outpatient management 3.
Risk Factors and Associated Conditions
- Placenta previa is associated with several risk factors, including prior cesarean delivery, advanced maternal age, and smoking 4.
- It is essential to assess for associated conditions like placenta accreta and vasa previa when placenta previa is diagnosed 4.
- A planned cesarean delivery is recommended in cases that persist into the late third trimester 4.
Prediction and Prevention of Hemorrhage
- Placenta previa poses a high risk for massive hemorrhage, and prenatal prediction of sudden bleeding during pregnancy and blood loss during Cesarean section can improve perinatal outcome 5.
- Ultrasonographic findings can be used to predict massive bleeding in cases of placenta previa 5.
- Prophylactic intraoperative uterine artery embolization has been shown to reduce hemorrhage and the need for blood transfusions in patients with major placenta previa 6.
Management Strategies
- A multidisciplinary approach to management, including ultrasound evaluation, hospitalization, antenatal corticosteroids, and scheduled cesarean section, can improve outcomes in patients with placenta previa 6.
- Outpatient management of symptomatic placenta previa may be an acceptable alternative to traditional conservative expectant inpatient management for selected patients 3.