From the Guidelines
Expectant management of placenta previa involves careful monitoring and activity restriction, with hospitalization recommended for patients with active bleeding or high-risk factors, while those with stable, asymptomatic previa may be managed as outpatients after 28 weeks with close surveillance and follow-up ultrasounds every 2-4 weeks. The management of placenta previa is crucial to prevent maternal and fetal morbidity and mortality due to the risk of uncontrolled vaginal bleeding. According to the study by 1, women with placenta previa after 28 weeks’ gestation are at risk for spontaneous labor and should avoid moderate to vigorous physical activity (MVPA), but maintain their activities of daily living and low-intensity activity, such as walking.
The criteria for outpatient management include no active bleeding for 48-72 hours, access to reliable transportation within 30 minutes of the hospital, stable vital signs, and adequate support at home. Antenatal corticosteroids, such as betamethasone, may be administered between 24-34 weeks to accelerate fetal lung maturity, as mentioned in the example answer. However, the most recent and highest quality study 1 does not provide specific guidance on the administration of antenatal corticosteroids.
Key aspects of expectant management include:
- Activity restriction, including pelvic rest with no intercourse or vaginal examinations
- Serial ultrasounds every 2-4 weeks to monitor placental location and cervical length, as recommended by 1
- Close surveillance for signs of bleeding or labor
- Planned cesarean delivery typically scheduled at 36-37 weeks for complete previa and 36-39 weeks for marginal previa, with earlier delivery considered in cases of significant bleeding, labor onset, or fetal distress. For Rh-negative mothers, anti-D immunoglobulin should be given after bleeding episodes, although this is not explicitly mentioned in the provided studies 1. The approach to expectant management of placenta previa should balance the risks of prematurity against the dangers of sudden hemorrhage, which can be life-threatening for both mother and fetus.
From the Research
Expectant Management of Placenta Previa
The expectant management of placenta previa involves several key components, including:
- Avoidance of digital vaginal examination 2
- Delay of delivery until 36 weeks' gestation and/or documented fetal lung maturity 2, 3
- Transfusion support to maintain maternal hematocrit greater than or equal to 30% 2
- Serial ultrasonography to monitor fetal growth and placental location 2, 3
- Antepartum fetal heart rate monitoring 2
- Glucocorticoids to promote fetal lung maturity 3
- Tocolytic therapy to prevent preterm labor 2, 4
- Elective delivery by cesarean section 2, 5
Inpatient vs. Outpatient Management
Studies have compared inpatient and outpatient management of symptomatic placenta previa, with one study finding no significant differences in outcomes between the two groups 3. However, outpatient management was associated with a significant reduction in maternal hospital days and costs 3. Another study reported successful outcomes with aggressive expectant management, including outpatient management and double setup examination prior to delivery 4.
Key Considerations
Other important considerations in the expectant management of placenta previa include:
- Assessment for associated conditions like placenta accreta and vasa previa 5
- Planned cesarean delivery in cases that persist into the late third trimester 5
- Anticipation of the clinical complication of placenta accreta to avoid serious consequences 6
- Clinical judgement and skill in the performance of cesarean sections and other uterine invasive techniques to minimize subsequent incidence of placenta previa 6