Abstract
BACKGROUND: The risk of retinopathy of prematurity (ROP) is associated with low birth weight and low gestational age. For ROP screening examination is recommended in infants weighing < or = 1500 g or of less than 32 weeks' gestational age. METHODS: From 1991 ROP screening was performed in 452 premature infants with either a birth weight < or = 1500 g (n = 303) or a birth weight > 1500 g (n = 149) and who required additional oxygen supplementation or underwent surgery with general anaesthesia before estimated term. RESULTS: Unexpectedly, three infants with birth weights between 2080 and 2325 g and a gestational age of 32 or 33 weeks developed stage 2 or 3 ROP. One of these underwent cryocoagulation. In three infants, preterm birth was induced by sudden placental abruption with severe prenatal blood loss followed by haemorrhagic shock. The umbilical cord packed cell volume was reduced to 0.14-0.19 (normal 0.43-0.63). All three infants underwent surgery with general anaesthesia within the first weeks of life. Of the remaining 449 infants none with a birth weight > 1650 g developed any stage of ROP. CONCLUSION: Severe prenatal blood loss requiring blood transfusions and surgery with general anaesthesia may induce higher stages of ROP even in infants with birth weights exceeding the usual screening criteria.