Right ventricular outflow tract obstruction in complicated monochorionic twin pregnancy

Area of Science:

• Perinatology
• Fetal Cardiology
• Maternal-Fetal Medicine

Background:

• Twin-to-twin transfusion syndrome (TTTS) is a serious complication of monochorionic twins.
• Recipient twins in TTTS are at risk for severe right ventricular outflow tract obstruction (RVOTO).
• Early identification and prediction of RVOTO are crucial for appropriate management.

Purpose of the Study:

• To evaluate pregnancy characteristics of neonates with RVOTO from complicated monochorionic twin pregnancies.
• To determine the incidence of RVOTO in TTTS cases.
• To construct a prediction model for RVOTO development in TTTS recipients.

Main Methods:

• Observational cohort study of monochorionic twin pregnancies with postnatal RVOTO diagnosis.
• Comparison of TTTS recipients with RVOTO versus controls (without RVOTO) treated with laser therapy.
• Ultrasound data analysis including pericardial effusion and ductus venosus (DV) flow patterns.

Main Results:

• RVOTO occurred in 3% of liveborn TTTS recipients.
• Predictors of RVOTO included pericardial effusion (45%), abnormal DV A-wave (73%), and earlier gestational age at laser therapy (17+3 weeks).
• RVOTO was also observed in TTTS donors and larger twins with selective intrauterine growth restriction (sIUGR).

Conclusions:

• RVOTO is a complication in TTTS recipients, donors, and fetuses with sIUGR.
• Abnormal DV flow, pericardial effusion, and early gestational age at TTTS onset predict RVOTO in recipients.
• Findings aid in developing diagnostic follow-up protocols for TTTS management.