Twin-twin transfusion syndrome
How is TTTS diagnosed?
Signs of the condition may be noted on a routine prenatal ultrasound, or your obstetrician may refer you for an ultrasound if your uterus measures larger than it should for your particular week of pregnancy. The discrepancy in measurement doesn't always mean that there is a problem.
But if a problem is suspected on the ultrasound, you may be referred to another doctor who specializes in high-risk cases for a more detailed Level 3 ultrasound.
Other tests you may encounter include:
- fetal echocardiography - a special ultrasound of a baby's heart
- a Doppler flow study -This lets your doctor assess blood flow in the umbilical blood vein and arteries, fetal brain and fetal heart
- magnetic resonance imaging (MRI) - to determine if there is any neurological damage in the donor twin; it takes pictures of the fetus's brain through the mother's abdomen
Ultrasound findings that point to a diagnosis of TTTS include identical twins with a shared placenta and abnormal communicating blood vessels.
You may also hear the term "stuck twin" which refers to the donor twin, who, with such little fluid in the sac is restricted in movement and can become stuck against the uterus.
When one twin dies there is a serious risk of death or severe neurological injury to the other fetus. Without treatment, death will occur in about 80 percent of these cases.