Correspondence (reply): In Reply

Hammerstein appropriately mentioned the raised concentration of HbF in the blood of very small premature neonates compared with children born at term, and the different oxygen binding curves. Global tissue hypoxia of prematurity can, however, not be deduced from this. In particular, the problem of retinopathy of prematurity mentioned by Hammerstein, which used to be substantial in the past, has been notably alleviated by improved ventilation regimens after applying exogenous surfactants (1). In our population, only 0.2% of children have been affected by bilateral blindness subsequent to retinopathy (2).

In our article we explained the relevant factors for a poor outcome (prematurity <26^th week of gestation, intraventricular cerebral hemorrhage, low maternal educational status). The physiologically raised HbF concentrations of premature babies, however, affect all children, including those with a good outcome. Effectively lowering of HbF concentration would be possible only by exchange transfusion, a maneuver that is associated with substantial risks, especially in this patient population. Relevant studies of such treatment are therefore missing in the literatures.

Further progress in terms of survival and the long-term development of extremely premature neonates can certainly be achieved in the specialisms of perinatology and neonatology. Our group of authors has contributed to analyzing the current healthcare situation. We do not, however, presume to question therapeutic regimens in neonatology.