December 7, 2015

Twin to Twin Transfusion SyndromeWhat is Twin to Twin Transfusion Syndrome?

Twin to twin transfusion syndrome (TTTS) is a rare, serious condition that can occur in pregnancies where two or more fetuses share a single placenta.  A majority of identical twins share a common placenta and as a result, the blood supplies of these fetuses can become connected. These connected blood vessels allow blood to circulate from one twin to the other.

Depending on the number, type and direction of the interconnecting blood vessels (anastomoses), this blood transfer can become disproportionate from one twin (referred to as the “donor”) to the other twin (referred to as the “recipient”).  This state of “flow imbalance” results in the recipient twin receiving more blood flow, while the donor twin receives too little.

In most cases, the donor twin will be smaller, pale in color, dehydrated, and often has anemia due to the low volume of blood. The recipient twin, on the other hand, will be larger in size, with a slight redness to the skin. Because of the higher blood volume received, the recipient twin may develop heart failure and require medicine to strengthen heart function.

TTTS usually begins to develop beginning in week 16 through week 25. This is a period of peak placental growth, which after week 25 begins to decelerate, and then eventually stopping after week 30.

TTTS occurs about 15% of the time among identical twins. Fraternal twins are not at risk for this syndrome because they do not share a placenta. In the US alone, there are at least 4,500 TTTS cases reported per year.

While TTTS is a random event, not known to be hereditary or preventative, great strides in technology have developed treatment options for this rare condition that include:

Adjusting Amniotic Fluid through Serial Amniocentesis

Serial Amniocentesis is a procedure involving the removal of excess amniotic fluid as needed throughout the pregnancy.  This extra fluid in the recipient twin can cause preterm labor, perinatal mortality, or tissue damage. In the case that the fluid does not re-accumulate, the reduction of amniotic fluid stabilizes the pregnancy.  This procedure is associated with a 66% survival rate of at least one fetus, with a 15% chance of cerebral palsy and average delivery occurring at 29 weeks gestation.

Adjusting Blood Supply through Laser Therapy

Laser surgery can also be used to seal off the connection between the blood vessels.  Each fetus remains connected to its primary source of blood and nutrition, the placenta, through the umbilical cord. This procedure is typically conducted only once and allows for shorter recovery time. Laser Therapy has been associated with 85% survival rate of at least one fetus, with a 5% risk of cerebral palsy and average delivery occurring at 33–39 weeks gestation.

Nutritional Therapy / Diet Supplementation

Some doctors also recommend bed-rest for the mother combined with massive intakes of protein as a therapy to try to counteract the syndrome. Diet supplementation appears to counter maternal metabolic abnormalities in identical twin pregnancies and improve perinatal outcomes in TTTS when combined with the standard therapeutic options. *Consult your doctor and medical team before considering any treatment options. 

TTTS Awareness

December 7th is World TTTS Awareness Day. The best defense against twin to twin transfusion syndrome is being educated and informed. Education on this life-threatening condition will empower you to fight TTTS with strength and a plan. If you have found out you are pregnant with multiples or have been diagnosed with TTTS, you are not alone. The Twin to Twin Transfusion Syndrome Foundation was established to provide you with immediate information about TTTS including the meaning of the medical terms, the various treatments available, premature labor and other complications of multiple pregnancy, and the value of bed rest and dietary supplements.

For more information on the TTTS Foundation, visit or call 1-800-815-9211.