What is a description of fetal twin-twin transfusion syndrome?
Fetal twin-to-twin transfusion syndrome (TTTS) is a rare pregnancy complication that occurs when identical (monozygotic) twins share the same placenta but have separate amniotic sacs. This condition arises due to abnormal connections or shunts within the shared placenta, leading to unequal blood flow between the twins. In TTTS, one twin, known as the donor twin, pumps excessive blood to the recipient twin through the shared vessels, while the recipient twin receives more blood than necessary.
The unequal distribution of blood flow can result in various complications that affect the health and well-being of both twins:
1. Polyhydramnios in the Recipient Twin: The recipient twin's amniotic sac may accumulate excessive amniotic fluid due to increased urine output from receiving extra blood. The distended amniotic sac can put pressure on the umbilical cord, leading to compromised blood flow and potential heart failure.
2. Oligohydramnios in the Donor Twin: On the other hand, the donor twin's amniotic sac may have insufficient amniotic fluid. This can lead to fetal compression, limb deformities, and pulmonary hypoplasia (underdevelopment of the lungs) due to limited lung growth.
3. Hemodynamic Issues: The altered blood flow affects the development and function of vital organs in both twins. The recipient twin may experience high blood pressure, heart failure, and liver dysfunction due to the overcirculation of blood. Conversely, the donor twin may have low blood pressure, anemia, and impaired kidney function from insufficient blood supply.
4. Growth Discordance: TTTS often results in noticeable growth differences between the twins. The recipient twin tends to be larger with increased body weight, while the donor twin may be smaller and malnourished.
5. Long-Term Health Risks: If TTTS is severe or left untreated, it can have long-term health consequences for both twins, such as neurological problems, developmental delays, cognitive impairments, and even death.
The diagnosis of TTTS involves ultrasound examinations to assess the amniotic fluid volume, blood flow patterns, and fetal growth. Once diagnosed, treatment options may include amnioreduction (removal of excess amniotic fluid), laser therapy to seal off the abnormal placental connections, or even fetoscopic surgery in severe cases.
Because of its potential severity, early detection and prompt medical intervention are crucial for improving the outcomes of TTTS pregnancies and ensuring the well-being of both twins.