Table 1 Incidence of ROP, mean gestational age at birth, and mean birth weight
ROP stageNo. (%)Mean gestational age (weeks) (range)Mean birth weight (g) (range)
No ROP73 (44)31.8 (27 to 36)1521 (900 to 2500)
Stage I53 (32)30.8 (25 to 35)1421 (790 to 3300)
Stage II25 (15)29.4 (26 to 34)1231 (650 to 2100)
Stage III13 (7.8)29.2 (25 to 34)1145 (750 to 1800)
Threshold2 (1.2)26.5 (25 to 28)775 (750 to 800)