Other studies have revealed the following: i.a prolonged ventilation in cases of early Hb levels of <15 g/dL at birth; VPs with higher early Hb levels have a reduced need for respiratory support and intensive care; and a low fraction of FHb during the first week of postnatal life is independently associated with the development of retinopathy in VP infants [13,31,32]. Here, GSTM1 is linked to retinal disorder.