Twin to Twin Transfusion Syndrome
General Information
Twin to Twin Transfusion Syndrome, often referred to as TTTS, only occurs with identical twins (whether in a twin pregnancy, or as part of a higher order multiple pregnancy). It is essentially an abnormality of the placenta where blood passes from one twin to the other through blood vessels in the shared placenta. The problem is that the blood is effectively transfused from one twin to the other, leaving the donor twin anaemic and often very small, while the larger recipient twin has too much blood circulating putting excessive strain on the heart.
The recipient twin often has extra amniotic fluid surrounding it, the donor twin very little. One of the early signs of TTTS in the middle trimester can be a sudden increase in size of the mother due to the large amounts of amniotic fluid surrounding one twin. Ultrasounds can be important in leading to a diagnosis, the key factors being significant differences in size of the babies, size of their bladders, and the amount of fluid surrounding each baby.
TTTS can occur at any time during the pregnancy. At it's most severe, it occurs before 20 weeks, usually resulting in a high mortality rate for one or both twins. TTTS can occur as late as during delivery of the babies, or even between the birth of the first and second baby. Where TTTS has been present for some time, it is often the larger twin who struggles more after the birth, having been working so hard pumping the extra blood.
Depending on when the diagnosis of TTTS occurs, and the extent to which it is affecting the babies, the treatment varies. It is possible to stop the transfusion of blood via laser treatment to seal off the blood vessels, however this treatment is relatively new in Australia (performed for the first time in Brisbane in early 2002?). Other treatments treat the symptoms rather than the cause, such as reducing the excess amniotic fluid from the recipient twin.
Internet Links
eMedicine - Twin to Twin Transfusion Syndrome
The Twin to Twin Transfusion Syndrome Foundation
Twin2Twin
Medline Plus Health Information - Fetal Transfusion Syndrome
Twin-Twin Transfusion Syndrome (TTTS)
Personal Stories
Mitchell and Antony 's Story
Joshua and Caleb's Story
