This form of treatment treats the cause of twin-twin transfusion syndrome (TTTS), i.e. blood vessel connecting the circulation of the two twins. A thin instrument called a fetoscope is inserted under ultrasound guidance through your abdominal wall into the cavity of the uterus to view the blood vessels in the placenta.  With a laser fibre, all vessels connecting the two twins are obliterated. In this way, the joint placenta is artificially divided in two. The excess amniotic fluid is also drained. The surgery can be done under local anaesthetic and sedation. For this procedure, you would be monitored in hospital for 24 hours.


  • There is a 10% risk of ruptured membranes after the procedure.
  • There is also a risk of premature delivery, with the average gestational age at delivery around 35 weeks.
  • There is a 5% risk for yourself to develop complications related to the procedure.
  • It can happen that not all the blood vessels could be seen to be lasered, which can cause TTTS to recur after the procedure. Even with a technically successful operation, one or both babies could die because of the severity of the TTTS, or as a result of having too small a share of the placenta.
  • In the best units, the survival rate of fetuses after laser treatment is 75%. This means that there is about a 50% chance that both survive, and a 25% chance that only one, or neither, would survive.
  • The risk of brain damage in surviving children is about 10%.

If you prefer, we can refer you to a centre in the Netherlands, Belgium or the United Kingdom until our own results are definitely equal to the best international results.



Photo of a placenta (after birth) showing blood vessels connecting the circulation of the twins.

TTTSsketsLongitudinal section through the uterus in TTTS.

(courtesy of prof. Jan Deprest, Louvain)