What problematic issue occurs in TTTS?

Twin-to-twin transfusion syndrome (TTTS) is a condition that arises in monochorionic twin pregnancies, where both twins share a placenta. The core issue in TTTS is indeed the unbalanced blood flow between the twins. This occurs due to differences in the connections of blood vessels within the shared placenta, which can lead to one twin receiving too much blood (the recipient twin) while the other receives too little (the donor twin). This imbalance can result in significant complications for both twins, including issues related to growth, heart function, and overall wellbeing.

The recipient twin may experience hypervolemia, leading to heart failure and excessive amniotic fluid, while the donor twin may suffer from hypovolemia, leading to growth restriction and oligohydramnios (reduced amniotic fluid). The severity of TTTS can lead to significant risks, including mortality or morbidity for one or both twins if not managed properly. Understanding the dynamics of blood flow in TTTS is crucial for timely and effective intervention, which can include procedures such as laser photocoagulation of the placental vessels.