Determination of serum ferritin in the evaluation of iron depletion and iron over load in chronic twin-to-twin transfusion syndrome.

In two pairs of twins with twin-to-twin transfusion syndrome serum ferritin levels were determined in order to estimate body storage of iron. Serum ferritin levels in the donor twins were found to be markedly lower than in the recipients and were below the lower limit found in normal neonates. One of the recipients was hydropic. His ferritin level was elevated far above the upper limit of normal. These findings support the hypothesis that in chronic twin-to-twin transfusion, depletion of iron stores occurs in the donor while the recipient suffers from iron overload. Determination of ferritin levels may be useful in the investigation of the twin-to-twin transfusion syndrome.