Is a cesarean section (CS) indicated for pregnant women with a large fundal posterior wall uterine myoma?

Cesarean Section for Large Fundal Posterior Wall Uterine Myoma

Cesarean section is NOT automatically indicated for pregnant women with a large fundal posterior wall uterine myoma; vaginal delivery should be attempted unless the myoma obstructs the birth canal or other specific obstetric complications arise. 1, 2

Primary Delivery Approach

• Vaginal delivery remains the preferred mode of delivery for women with uterine myomas, including large ones, as cesarean section carries significantly higher maternal morbidity (5-7 times more infections, higher rates of postpartum fever, endometritis, wound infections, and venous thromboembolism) without providing additional benefits in most cases. 2

• Cesarean section should be reserved strictly for obstetric indications, not simply based on the presence of a myoma, even if large. 1, 2, 3

Specific Indications for Cesarean Section

Cesarean section IS indicated when:

• The myoma physically obstructs the birth canal (particularly cervical or lower segment myomas that block fetal descent). 3

• Other obstetric complications coexist that independently warrant cesarean delivery. 3

• Placental abruption occurs, which is more common with myomas >200 cm³ or when the placenta is superimposed over the myoma. 4

Critical Assessment During Pregnancy

Ultrasound evaluation should specifically document:

• Myoma size, location, and position relative to the placenta and lower uterine segment. 4, 3

• Relationship to the placenta, as retroplacental myomas carry higher risk of abruption. 4, 3

• Echogenic structure (heterogeneous patterns or cystic areas suggest higher complication risk). 4

• Serial monitoring during the second and third trimesters when hemodynamic load is highest. 1

Location-Specific Considerations

Fundal posterior wall location (as in your question):

• Does NOT obstruct the birth canal, making vaginal delivery feasible in most cases. 4, 3

• May complicate cesarean section if performed, as posterior myomas can make uterine incision placement and fetal extraction more challenging. 5

• Cervical myomas require the most careful management and are more likely to necessitate cesarean delivery due to birth canal obstruction. 3

Important Caveats

Common pitfalls to avoid:

• Do not perform prophylactic cesarean section based solely on myoma presence or size, as this increases maternal risks without proven benefit. 2, 3

• Avoid myomectomy at the time of cesarean section unless absolutely necessary, as it carries significant hemorrhage risk (three cases requiring hysterectomy in one series of nine cesarean myomectomies). 4

• If cesarean section becomes necessary for other reasons, be prepared for potential surgical challenges including difficulty accessing the lower uterine segment (may require vertical corporeal incision) and increased bleeding risk. 5

Risk Stratification

Higher-risk myomas requiring closer surveillance:

• Size >200 cm³ (associated with increased pelvic pain and abruption risk). 4

• Submucosal location (higher complication rates). 4, 3

• Multiple myomas (increased risk profile). 4, 3

• Retroplacental position (significantly increased abruption risk). 4

Expected complications occur in only 10-30% of pregnant women with myomas, and most can be managed expectantly without requiring cesarean delivery. 3