Retinopathy of prematurity in Ardabil, North West of Iran: Prevalence and risk factors

Retinopathy of prematurity (ROP), which affects the retina of premature infants, is a leading cause of blindness in premature infants worldwide. The aim of this study was to evaluate the frequency and risk factors of retinopathy of prematurity infants referred to Alavi hospital between October 2018 and October 2019. In the present study, 400 infants with gestational age less than 34 weeks and or birth weight of 2000 g or less were enrolled in the study. Required information including sex, gestational age, maternal age, birth weight, type of delivery, oxygen therapy, septicemia, multiple gestations, consanguineous marriage, respiratory problem, and blood exchange were extracted from their hospital records and then included in the data collection form. These infants were also examined for ROP, stage and area of involvement by an experienced ophthalmologist and then classified into two groups including retinopathy and healthy group. Finally, the data were analyzed in SPSS 25 software using chi-square, fisher exact test, t-test, binary logistic regression, and ROC curve analysis. Of the 400 preterm infants studied (57.2% male and 42.8% female), 107 (26.8%) infants had ROP of whom 23 (21.5%) needed treatment (i.e. 5.8% of all infants need treatment). There were 4 (3.7%), 29 (27.1%), and 74 (69.2%) infants with zone I, II, and III, respectively. There were 91 (85%), 11 (10.3%), and 5 (4.7%) infants with stage I, II, and III, respectively. Multivariate logistic regression analysis showed that parental consanguinity (OR=2.263, 95%CI: 1.240-4.130, P=0.008), gestational age less than 32.5 weeks (OR=4.067, 95%CI: 2.340-7.069, P<0.001), and birth weight less than 1725 g (OR=4.522, 95%CI: 2.677-7.637, P<0.001) were associated with a 2.3-fold, 4.1-fold, and 4.5-fold increased risk of ROP, respectively. ROP had no significant relationship with other variables. In summary, the findings of the present study showed that one quarter of the premature infants had ROP. Furthermore, birth weight less than 1725 g, gestational age less than 32.5 weeks, and parental consanguinity were risk factors for ROP, in addition, one-fifth of the infants with ROP needed treatment.