Twin-To-Twin Transfusion Syndrome

Diagnosis of twin-to-twin transfusion syndrome

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Twin-to-twin transfusion syndrome is diagnosed with the aid of ultrasound. The donor foetus has very little fluid in its amniotic sac (oligohydramnios) and its bladder is either undetectable or abnormally small because it produces hardly any urine. The recipient, on the other hand, tends to have a large volume of amniotic fluid in its sac (polyhydramnios) and a very swollen bladder due to increased urine production.

There is sometimes an obvious disparity between the foetuses in terms of estimated weight and size, the recipient being larger than the donor; however, in itself this does not represent a diagnostic criterion.

Two essential criteria must be met before making the diagnosis:

Embrión con bolsa grande

Polyhydramnios in the amniotic sac of the recipient foetus. Polyhydramnios is diagnosed when the height of the largest vertical column of amniotic fluid exceeds 8 cm.

embrión con bolsa muy pequeña

Oligohydramnios in the amniotic sac of the donor foetus. Oligohydramnios is defined as a largest vertical column of amniotic fluid of less than 2 cm.

Substantiated information by:

Mar Bennasar
María Marí

Published: 20 February 2018
Updated: 20 February 2018


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