How should a hemodynamically stable 32‑week pregnant woman with known placenta previa and mild painless vaginal bleeding be managed, including imaging, corticosteroid administration, and timing of cesarean delivery?

Management of 32-Week Placenta Previa with Slight Bleeding

A hemodynamically stable woman at 32 weeks with known placenta previa and mild vaginal bleeding should undergo immediate transvaginal ultrasound with Doppler to assess placental location, cervical length, and exclude vasa previa, followed by administration of corticosteroids and expectant management with planned cesarean delivery at 34–36 weeks unless bleeding worsens. 1

Immediate Diagnostic Evaluation

Ultrasound imaging is the cornerstone of management and must be performed before any digital cervical examination. 2, 3

• Transvaginal ultrasound is safe even with known placenta previa and provides superior visualization of the cervix and lower uterine segment compared to transabdominal approach alone. 4, 1

• The comprehensive ultrasound assessment must include:

  • Exact measurement of the distance from the placental margin to the internal cervical os (overlap ≥15 mm predicts persistence at delivery). 1
  • Evaluation for placental abruption, though ultrasound identifies at most 50% of cases; identification is associated with worse perinatal outcomes. 4, 1
  • Cervical length assessment, as a short cervix with bleeding significantly increases preterm delivery risk. 4, 1
  • Doppler evaluation to exclude vasa previa, as vessels overlying the internal os can be subtle but carry risk of fetal exsanguination. 4, 1, 5
  • Assessment of the lower uterine segment thickness (<2.5 mm suggests risk of uterine rupture, especially with prior cesarean). 4

• Digital pelvic examination is absolutely contraindicated until placenta previa has been definitively excluded, as examination can trigger life-threatening hemorrhage. 2, 3, 1

Risk Stratification for Placenta Accreta Spectrum

All women with placenta previa and any prior cesarean deliveries must be evaluated for placenta accreta spectrum disorder, which increases morbidity 7-fold after one prior cesarean to 56-fold after three cesarean deliveries. 1, 6

• Additional risk factors include advanced maternal age, high parity, prior uterine surgery, smoking, hypertension, and in vitro fertilization. 1

Corticosteroid Administration

Antenatal corticosteroids should be administered immediately when delivery is anticipated before 37 weeks, which applies to this 32-week patient with bleeding. 1

• Corticosteroids promote fetal lung maturation and should be given at this gestational age to prepare for potential preterm delivery. 5, 7

Expectant Management Strategy

For hemodynamically stable patients with mild bleeding, expectant management is appropriate with close monitoring rather than immediate cesarean delivery. 8, 7, 9

• Hospitalization is required for active bleeding, though selected stable patients may be candidates for outpatient management after initial stabilization (≥72 hours without recurrent bleeding). 1, 9

• Activity restrictions after 28 weeks include avoiding moderate-to-vigorous physical activity while maintaining activities of daily living and low-intensity walking. 1

• Serial monitoring includes:

  • Frequent vital signs and continuous or intermittent fetal heart rate monitoring. 8
  • Serial hemoglobin measurements to guide transfusion decisions. 1, 8
  • Hemoglobin values should be maximized with oral or intravenous iron to prepare for potential hemorrhage at delivery. 1

Timing of Delivery

Cesarean delivery should be planned at 34–36 weeks of gestation for uncomplicated placenta previa, balancing neonatal complications against increased maternal bleeding risk after 36 weeks. 1

• Delivery should not be delayed beyond 36 weeks, as approximately 50% of women with placenta accreta spectrum beyond 36 weeks require emergent delivery for hemorrhage. 1

• Earlier delivery is indicated if:

  • Heavy or recurrent bleeding occurs (approximately 62% of patients experience recurrent bleeding episodes). 9
  • Fetal heart rate abnormalities develop. 8
  • Hemodynamic instability ensues despite resuscitation. 1

Delivery Planning

Delivery must occur at a level III or IV maternal care facility with multidisciplinary expertise including maternal-fetal medicine, pelvic surgeons, urologists, interventional radiologists, obstetric anesthesiologists, and neonatologists. 1

• The blood bank should be notified in advance due to frequent need for large-volume transfusion; approximately 15% of patients require blood transfusion. 1, 9

• Massive transfusion protocol should be activated early if significant bleeding occurs, with transfusion of packed red blood cells, fresh frozen plasma, and platelets in a 1:1:1 to 1:2:4 ratio. 1

Critical Pitfalls to Avoid

• Normal vital signs do not exclude significant placental pathology such as placental abruption, which can present with normal hemodynamics initially but rapidly deteriorate. 3

• The amount of visible blood loss does not always correlate with the seriousness of the etiology; even small amounts warrant careful evaluation. 8

• Approximately 62% of patients will experience recurrent bleeding episodes, requiring readiness for expeditious cesarean delivery. 9

• Transvaginal ultrasound is explicitly safe and should not be avoided in placenta previa; it is the gold standard with 90.7% sensitivity and 96.9% specificity. 1, 6