What is the most appropriate next step in management for a 24-week pregnant woman with monochorionic (having a single placenta and one chorion) twin pregnancy and twin-to-twin transfusion syndrome (TTTS)?

Fetoscopic Laser Photocoagulation is the Standard Treatment

For a 24-week pregnant woman with monochorionic twin pregnancy and TTTS, fetoscopic laser photocoagulation of placental vascular anastomoses (Option C) is the most appropriate next step in management. 1

Why Fetoscopic Laser Surgery is the Clear Choice

• The Society for Maternal-Fetal Medicine explicitly recommends fetoscopic laser surgery as the standard treatment for stage II through stage IV TTTS presenting between 16 and 26 weeks of gestation. 1 This patient at 24 weeks falls squarely within this therapeutic window.

• Fetoscopic laser surgery provides superior survival rates compared with expectant management or serial amnioreduction, which were historical alternatives that are no longer considered standard of care. 1

• This is the only therapy that directly addresses the underlying pathophysiology by photocoagulating intertwin placental anastomoses, functionally "dichorionizing" the placental circulation and eliminating the root cause of TTTS. 1, 2

Expected Survival Outcomes

Current data from experienced fetal care centers demonstrate:

• Dual survivors in 50-70% of cases 1
• At least one survivor in 70-90% of cases 1, 2
• No survivors in 10-20% of cases 1

These outcomes are substantially better than expectant management alone, making Option B (expectant management) inappropriate. 1

Why Other Options Are Incorrect

Termination of pregnancy (Option A) is not indicated unless the patient specifically requests it or there are major fetal anomalies incompatible with life. 1 The survival data clearly support intervention rather than pregnancy termination.

Cesarean section (Option D) at 24 weeks would result in extreme prematurity with very poor neonatal outcomes and does not address the underlying TTTS pathophysiology. 1

Technical Considerations for the Procedure

• The procedure uses a percutaneous access technique and can be safely performed with maternal intravenous sedation and local anesthesia or regional anesthesia; general anesthesia is rarely necessary. 1

• The Solomon technique is preferred, which involves linear photocoagulation along the intertwin vascular equator after ablating visible anastomoses, reducing the risk of recurrent TTTS or twin anemia-polycythemia sequence (TAPS). 1, 3

• Complete visualization of the vascular equator is the primary determinant for successful TTTS treatment. 3

Common Complications to Anticipate

• Preterm premature rupture of membranes (PPROM) is the most common complication, occurring in approximately 25% of cases. 1

• Recurrent or reversed TTTS or TAPS may complicate over 10% of pregnancies post-laser. 1

• While most pediatric survivors have normal neurologic outcomes, major neurologic morbidity occurs in 4-18% of survivors at 2 years of age. 1 This risk is multifactorial, including prematurity and the underlying TTTS pathophysiology.

Critical Management Pitfall

Do not delay referral to a specialized fetal care center with expertise in fetoscopic laser surgery. 1 Time is critical, as the therapeutic window extends only to 26 weeks of gestation, and this patient is already at 24 weeks. 1

Ancillary Management

• Administer antenatal corticosteroids for fetal lung maturation at this gestational age (24 weeks), particularly given the increased risk of preterm delivery following the procedure. 4