Urine VEGF Levels in Very Low Birth Weight (VLBW) Infants

VLBW infants are at risk of developing retinopathy of prematurity (ROP). In the first phase of ROP there is a down-regulation of retinal VEGF-expression because of postnatal relative hyperoxia, followed by an upregulation of VEGF mediated through retinal hypoxia, which leads to pathologic vessel formation. VEGF acts through binding to the specific receptor FLT-1, the soluble form sFLT-1 is a specific antagonist of VEGF action. Erythropoietin, given to VLBW infants to prevent anemia, may stimulate VEGF-production in neuronal cells. Currently, there are no data published about VEGF urine-levels in VLBW infants and it is not known, if urine VEGF-levels may serve as a non-invasive marker of ROP-risk. Further shall be investigated, if erythropoietin-therapy increases urine VEGF-levels and if there is a correlation with ROP-development.

Inclusion Criteria:

• gestational age < 32 weeks
• birth weight <1500g

Exclusion Criteria:

• absent written consent by parents
• connatal eye malformation