Delivery Timing for Persistent Placenta Previa at 36-37 Weeks
For this patient with persistent placenta previa at 36-37 weeks without bleeding, cesarean delivery should be performed between 36 0/7 and 37 0/7 weeks of gestation, making option (c) correct. 1, 2
Optimal Delivery Timing
The American College of Obstetricians and Gynecologists recommends planned cesarean delivery at 34 0/7 to 35 6/7 weeks for placenta previa with suspected placenta accreta spectrum disorder. 3, 1, 2
However, for uncomplicated placenta previa without evidence of accreta, delivery can be safely deferred until 36-37 weeks in stable patients without significant hemorrhage. 4
Delivery should not be delayed beyond 36 0/7 weeks because approximately 50% of women with placenta accreta spectrum beyond 36 weeks require emergent delivery for hemorrhage. 1, 2
The timing balances neonatal morbidity from prematurity against the dramatically increasing risk of maternal hemorrhage as gestational age advances. 1
Critical Risk Assessment for This Patient
This patient has two major red flags that substantially elevate her risk for placenta accreta spectrum disorder:
In vitro fertilization is an identified risk factor for placenta accreta spectrum. 3, 2
Persistent placenta previa is the single most important risk factor for placenta accreta spectrum, present in 49% of accreta cases. 3, 2
If this patient has any prior cesarean deliveries, her risk increases 7-fold after one cesarean to 56-fold after three cesareans. 3, 2
The combination of placenta previa and prior uterine surgery creates the highest risk scenario for abnormal placental invasion. 2
Why Other Options Are Incorrect
Option (a) - Delivery between 34-35 weeks: This timing is specifically recommended for suspected placenta accreta spectrum disorder, not uncomplicated placenta previa. 3, 1 Without confirmed accreta, earlier delivery unnecessarily exposes the neonate to prematurity complications. 1
Option (b) - "Double set up" delivery: This outdated approach (attempting vaginal delivery in the operating room with immediate cesarean capability) is not indicated for placenta previa. 5, 6 Cesarean delivery is the definitive management for persistent placenta previa at term. 5, 6
Option (d) - Regional anesthesia contraindicated: This is false. Regional anesthesia (spinal or epidural) is safe and appropriate for cesarean delivery in women with placenta previa. 6 General anesthesia is reserved for cases with active massive hemorrhage requiring immediate intervention.
Essential Preoperative Planning
Delivery must occur at a level III or IV maternal care facility with multidisciplinary expertise, including maternal-fetal medicine, pelvic surgeons, obstetric anesthesiologists, and blood bank with massive transfusion protocols. 3, 1, 2
Preoperative coordination with anesthesiology, neonatology, and expert pelvic surgeons is essential. 1
Notify the blood bank in advance due to frequent need for large-volume blood transfusion. 1
Optimize hemoglobin values during pregnancy and treat anemia with oral or intravenous iron as needed. 1
Intraoperative Considerations
Make the uterine incision away from the placenta when possible. 1
If placenta accreta spectrum is encountered, leave the placenta in situ—attempts at forced placental removal cause profuse hemorrhage and should be avoided. 1, 2
Cesarean hysterectomy may be necessary if placenta accreta spectrum is confirmed. 1, 2
Have a contingency plan for emergent management, as patients with placenta previa are at increased risk of prepartum hemorrhage. 3, 1
Common Pitfalls
Failure to evaluate for placenta accreta spectrum in women with placenta previa and risk factors (IVF, prior cesarean) can lead to catastrophic hemorrhage. 1, 2
Delaying delivery beyond 36 weeks significantly increases the risk of emergent delivery for hemorrhage. 1, 2
Attempting vaginal delivery or manual placental removal when accreta is present causes life-threatening hemorrhage. 1, 2