The influence of global external factors on the incidence trends of retinopathy of prematurity in Western Ukraine

Background. Between 2019 and 2024, Ukraine’s healthcare system was subjected to considerable stress due to two global crises: the COVID-19 pandemic (2020–2021) and the full-scale war beginning in 2022. These events posed new challenges to the organization of medical care and the healthcare system in gene­ral and contributed to chronic stress in the Ukrainian population. Therefore, the influence of such factors should be considered in the context of the prevalence and course of retinopathy of prematurity (ROP). Aim: to investigate the impact of global external factors on the incidence of ROP in the Western region of Ukraine. Mate­rials and methods. A retrospective clinical study was conducted at the Ivano-Frankivsk Regional Children’s Hospital, including 1341 preterm infants with gestational age (GA) < 37 weeks. Data from 2019 to 2024 were analyzed. Results. Cumulative ROP incidence in 2019 was 14.9 %, the lowest during the observation period. In 2020–2021, it increased to ~ 19 %, coinciding with the COVID-19 pandemic. In 2022, amid full-scale war, the incidence rose sharply to 32.1 % (p = 0.0034), the highest level, followed by a partial decline in 2023–2024, likely reflecting the healthcare system’s adaptation. The proportion of ROP among infants with GA < 28 weeks reached 52 % compared to 9–19 % in those with GA 28–36 weeks, peaking in 2022. All observation years showed statistically significant differences between these groups (χ² = 3.86–37.03; p < 0.005). Population analysis revealed an increase in the proportion of infants with GA < 28 weeks among all ROP cases — from 8 % in 2019 to 22 % in 2022. Risk assessment confirmed consistently high values in the < 28-week group: risk ratio 3.5–4.5, odds ratio 7–11 (highest in 2022–2024), indicating additional epidemiological burden due to population structure shifts. Trend analysis and time series decomposition confirmed that the 2022 increase in ROP incidence was not random but structurally driven. The ADF test confirmed non-stationarity of the time series. In 2022, the share of severe ROP stages (3–5) exceeded 40 %, whereas mild stages prevailed (> 70 %) in 2019–2021. The frequency of aggressive forms peaked, and spontaneous regression rates decreased. Analysis of the time at ROP onset and clinical subtype showed that in aggressive forms, the mean postmenstrual age was lowest (32.7 weeks), while non-complicated forms had the highest one (35.5 weeks); this association was statistically significant (ANOVA: F = 33.64; p < 0.001). Conclusions. Global external factors significantly influenced ROP incidence, severity, and changes in the population structure of preterm infants. Extreme prematurity (GA < 28 weeks) remains the primary determinant of high ROP risk. Analysis of the onset time may serve as a prognostic marker of severe disease and help tailor personalized risk stratification and optimize screening programs.