Circulating Nucleated Red Blood Cell Counts at Birth Among Preterm Neonates Who Subsequently Developed Retinopathy of Prematurity.

Purpose: Retinopathy of prematurity is a leading cause of childhood blindness, with several predisposing factors, including prematurity and oxygen therapy. This study examines nucleated red blood cell (NRBC) counts at birth in preterm neonates and compares those who developed ROP with those who did not.

Methods: This case-control study included 143 preterm neonates (birth weight <1500 g and/or gestational age <32 weeks) born at Ghaem Hospital, Mashhad, between 2017 and 2020. Umbilical cord blood samples were collected to measure NRBC counts per 100 white blood cells. Neonatal characteristics (birth weight, sex, gestational age, Apgar scores), maternal history (age, pregnancy complications, mode of delivery, parity), and laboratory findings were recorded. Follow-up assessments continued until discharge, with ophthalmologic evaluation for ROP at 32 weeks of gestational age or four weeks post-birth. The control group consisted of preterm neonates without ROP.

Results: Among the 143 neonates studied, 102 (71.3%) developed ROP, while 41 (28.7%) did not. Significant differences were observed between the two groups in NRBC percentage ( = 0.009) and fifth-minute Apgar score ( = 0.002).

Conclusions: Elevated umbilical cord NRBC counts, alongside other clinical markers, may serve as a predictive factor for ROP and its severity.