Role of fetal hemoglobin in the development and progression of retinopathy of prematurity in preterm infants.

Purpose: The objective of this study was to find the association between fetal hemoglobin (HbF) concentration and retinopathy of prematurity (ROP) in preterm infants.

Methods: In this observational, prospective, longitudinal study, a total of 410 preterm infants with <36 gestational weeks and <2.5 kg birth weight, who were attending ROP clinic in a tertiary care hospital of central India for 1 year duration were included. Dilated fundus examination was done as per ROP screening guidelines, and ROP was staged as per international classification for retinopathy of prematurity (ICROP) classification, 2021. HbF (%) was measured with high-performance liquid chromatography, and data was analyzed statistically. The relationship between HbF (%) and ROP was evaluated. Those infants who had ROP were further divided into treatment-requiring and non-treatment-requiring groups and HbF was compared in these groups at the first visit and after 1-month follow-up period. The outcome of ROP was studied with HbF levels.

Results: A total of 410 preterm infants were included, out of which 110 infants had ROP (26.8%). Infants with ROP had significantly lower percentage of HbF with gestational age groups and birth weight groups, compared to infants without ROP. Higher percentage of HbF was associated with a lower prevalence of ROP. Higher concentration of HbF was found in the ROP infants who regressed spontaneously without treatment and less concentration was found in those who progressed to a severe disease and those who required treatment. The predictive ability of HbF (%) was 0.976 for ROP.

Conclusion: Low fraction of HbF was found to be significantly associated with the development and progression of ROP.