Monochorionic Pregnancies & Twin to Twin Transfusion Syndrome (TTTS)
To find out more about Twin to Twin Transfusion Syndrome (TTTS), download our TTTS Guide for parents and booklet of inspiring parents' stories. You can also sign up for our Twin to Twin Transfusion Syndrome (TTTS) support group on facebook.
Below leading TTTS consultant, Dr Ruwan Wimalasundea answers all your frequently asked questions:
What is Twin to Twin Transfusion Syndrome (TTTS)?
More than six per cent of mothers who responded to Tamba’s 2008 survey said their babies were affected by Twin to Twin Transfusion Syndrome (TTTS). While the condition is rare, Tamba wants to do more to help families whose twins were affected by it.
TTTS affects twins who share not only a placenta but also some of the same circulation, resulting in the transfusion of blood from one twin (the donor) to the other (the recipient) in the womb. In most cases the donor twin may become smaller and anaemic due to not having enough blood supply. The recipient twin has a higher blood volume, which can strain the foetus’s heart and lead to heart failure.
The donor twin is also likely to have a decreased urinary output, leading to a lower than normal level of amniotic fluid, whereas the reverse is true for the recipient twin. The excess fluid in the recipient twin (polyhydramnios) can be quite uncomfortable for the pregnant mother and pressure on the cervix can lead to ruptured membranes and early delivery.
During your first ultrasound scan, the sonographer will look to see if your twins are monochorionic (one chorionic membrane) and, if so, your pregnancy will be closely monitored for signs of TTTS. Indications of TTTS include differences in the size of the twins’ abdomens, estimated birth weights, amounts of amniotic fluid and bladder volumes.
If diagnosed, health professionals will continue to monitor your pregnancy carefully with frequent ultrasound examinations. You may be referred to a specialist centre for laser ablation therapy, which separates the blood vessels in the placenta.
Below a mother shares her experience of being diagnosed with TTTS: