Management of Third Trimester Placenta Previa
The correct answer is D: advice bed rest and avoid sexual intercourse. Digital pelvic examination must be strictly avoided, vigorous exercise should be restricted after 28 weeks, and while iron supplementation is beneficial, the priority is activity restriction and avoiding triggers for hemorrhage 1, 2.
What Must Be Avoided
Digital pelvic examination is absolutely contraindicated until placenta previa has been excluded, as it can trigger catastrophic hemorrhage 3, 1, 2. This is a critical safety principle emphasized across all major guidelines.
- Vigorous or moderate-to-vigorous physical activity should be avoided after 28 weeks gestation in women with placenta previa 1, 2, 4
- Sexual intercourse should be avoided due to risk of triggering bleeding 1
- Any activity that could provoke uterine contractions or cervical trauma must be restricted 5
Recommended Activity Level
- Before 28 weeks: Women with asymptomatic placenta previa can continue moderate-to-vigorous physical activity 1, 2, 4
- After 28 weeks: Restrict to activities of daily living and low-intensity activity such as walking only 1, 2, 4
- Active bleeding requires hospitalization 1, 4
Iron Supplementation and Anemia Management
While not the primary intervention, optimizing hemoglobin is important:
- Hemoglobin values should be maximized during pregnancy by treating anemia with oral or intravenous iron as needed 1, 4
- This prepares for potential hemorrhage at delivery, which is the primary cause of maternal morbidity and mortality in placenta previa 2
Essential Diagnostic Considerations
- Transvaginal ultrasound (not digital examination) is the gold standard for diagnosis with 90.7% sensitivity and 96.9% specificity 2, 4
- All women with placenta previa and prior cesarean deliveries must be evaluated for placenta accreta spectrum disorder, as risk increases 7-fold after one cesarean to 56-fold after three cesareans 1, 2, 4
Delivery Planning
- Planned cesarean delivery at 34 0/7 to 35 6/7 weeks gestation is recommended for uncomplicated placenta previa 1, 2, 4
- Delivery should not be delayed beyond 36 0/7 weeks, as approximately 50% of women with placenta accreta spectrum beyond 36 weeks require emergent delivery for hemorrhage 1, 2, 4
- Delivery must occur at a level III or IV maternal care facility with adequate blood banking facilities and multidisciplinary expertise 4
Common Pitfalls
- Never perform digital pelvic examination - this is the most dangerous error and can precipitate life-threatening hemorrhage 3, 1, 2
- Do not encourage vigorous exercise after 28 weeks - this increases risk of bleeding 1, 2
- Do not delay evaluation for placenta accreta spectrum in women with prior cesarean deliveries - failure to diagnose can lead to catastrophic hemorrhage 1
- Outpatient management may be considered for asymptomatic patients without prior bleeding episodes, but this requires careful patient selection and close monitoring 6