Abstract:

Objective    To investigate the incidence of retinopathy of prematurity (ROP) in extremely low birth weight infants (ELBWI) and very low birth weight infants (VLBWI) and to explore its risk factors. Methods    A retrospective analysis was carried out for the screened 53 ELBWI and 974 VLBWI. Comparison of ROP incidence between ELBWI and VLBWI groups was statistically analyzed. Birth weight, gestational age and gender between ROP and non-ROP groups, and mild ROP group and severe ROP group were compared. Results    23/53 ELBWI developed ROP with an incidence of 43.4%, while 15 of them developed severe ROP with an incidence of 28.3%. 177/974 VLBWI developed ROP with an incidence of 18.2%, while 33 of them developed severe ROP with an incidence of 3.4%. The difference of ROP incidence between ELBWI and VLBWI was statistically significant (χ2＝20.39，P<0.001), while the differences of birth weight (χ2=20.39，P<0.001) and gestational age (χ2=50.06，P<0.001) between ROP group and nonROP group were statistically significant. Also, the differences of birth weight (χ2=24.21，P<0.001) and gestational age (χ2=53.67，P<0.001) between mild ROP group and severe ROP group were statistically significant. Conclusions    The incidences of ROP and severe ROP in ELBWI are higher than those in VLBWI. ROP risk factors are various and mainly include gestational age less than or equal to 28 weeks and low birth weight.

Key words: Very low birth weight infants, Birth weight, Risk factors, Extremely low birth weight infants, Gestational age, Retinopathy of prematurity