Twin to Twin Transfusion Syndrome (TTTS)

This phenomenon occurs when there is an imbalance in the arteriovenous shunting of blood from one twin to the venous circulation of the other twin.

It occurs exclusively in monozygotic twins, especially monochorionic diamniotic twins.

Clinical manifestations

Donor twin

1. Smaller of the two
2. Oligohydramniotic- due to oliguria and renal insufficiency
3. Anemic
4. Hypotensive- due to hypovolemia

Death results from anemia

The donor twin has better chances of survival compared to the recipient twin.

Recipient twin

1. Large
2. Polyhydramniotic
3. Polycythemic
4. Hypertensive- due to hypervolemia

Death results from hyperviscosity and congestive cardiac failure

The recipient twin has poor chances of survival due to increased risks of neural tube defects and other congenital anomalies

Diagnosis

Antenatal ultrasound- monitor and detect physical signs of twin to twin transfusion

Doppler blood flow of the chorionic placenta- check for imbalance in placental blood flow

Management

Therapeutic amniocentesis to control polyhydramnios in the recipient twin

Septostomy- connecting the two amniotic sacs through a hole to prevent amniotic fluid imbalance

Laser photocoagulation to reduce the anastomotic inequality in the chorionic plate

Feticide- is done when the survival of one twin is unlikely