Factors affecting ROP development in first 8 weeks after birth

The study included 675 preterm infants who were hospitalised in a neonatal intensive care unit. Image credit: ©ondrooo – stock.adobe.com

A recent study that analysed independent risk factors for the development of retinopathy of prematurity (ROP) in preterm infants found that low birth weight, blood transfusion, necrotising enterocolitis, bronchopulmonary dysplasia and antenatal steroid and surfactant therapies significantly affected the development of ROP.1 According to this analysis, postnatal weight gain may not be an accurate predictor of ROP development after adjusting for confounding factors, reported Mustafa Yildirim, MD, and Asuman Coban, MD, the first authors of the study. Both are from the Department of Pediatrics, Division of Neonatology, Istanbul University Faculty of Medicine, Istanbul, Turkey. Ozgul Bulut, MD, Nur Kir Mercül, MD, and Zeynep Ince, MD,joined Drs Yildirim and Coban in the study.

Weight gain in infants has been evaluated in a number of studies,but the jury still seems to be out on how or if weight affects the development of ROP, the authors pointed out. However, the available information about this subject has been less than clear regarding poor postnatal weight gain and its association with ROP, despite that poor weight gain among these infants has been reported to be a strong indicator of ROP development.2-5

Drs Yildirim and Coban conducted this study to clarify the relationship between postnatal weight gain and ROP development during the first 8 weeks of life and identify other potential risk factors for development of ROP in preterm infants.

Population-based retrospective cohort study

The study included 675 preterm infants who were hospitalised in a neonatal intensive care unit. All had a gestational age of 32 weeks or less. The authors obtained the infants’ demographic characteristics, clinical findings and weekly weight gain (g/kg/day) during the first 8 weeks from their medical records.

The authors reported that the incidence of ROP in the study infants was 41% (n=278), and 13.3% (n=37) of them required treatment. Among the infants in whom ROP developed, the mean birth weight and gestational age were significantly lower than among the infants in whom ROP did not develop (973 ± 288 grams and 1,301 ± 349 grams, P=0.001 and 28.48 ± 1.95 weeks and 30.08 ± 1.60 weeks,
P=0.001, respectively).

With the decrease in the gestational week and birth weight, ROP development and the risk of ROP that required treatment increased. In the infants who developed ROP, the mean weight gain in the postnatal third week was significantly lower compared to those in the group that did not develop ROP (13.9±8.2 grams and 15.4±6.8 grams, P =0.034).

Multiple logistic regression analysis showed that in addition to low birth weight (<750 grams) (odds ratio [OR], 8.67; 95% confidence interval [CI], 3.99–18.82,
P=0.001), blood transfusion (OR, 2.39; 95% CI, 1.34–4.24, P=0.003), necrotising enterocolitis (OR, 4.79; 95% CI, 1.05–26.85, P=0.045), bronchopulmonary dysplasia (OR, 2.03; 95% CI, 1.22–3.36, P =0.006), antenatal steroid therapy (OR, 1.60; 95% CI, 1.05–2.43, P =0.028) and surfactant administration (OR, 2.06; 95% CI, 1.32–3.2, P=0.001) were independent risk factors for ROP development.

These results led the authors to report that postnatal weight gain may not accurately predict development of ROP as reported in previous investigations.

The main strength of this study, according to the investigators, is that it was the most comprehensive study that evaluated the risk factors in the development of ROP among the studies conducted to this date. However, because of inherent limitations, they advised that prospective multicentre cohort studies be conducted to study relationships between postnatal weight gain and ROP.

They concluded, “Postnatal weight gain, as predicted in previous studies, may not be an accurate predictor of ROP development after adjusting for confounding factors. However, the analysis of independent risk factors that influenced the development of ROP revealed a statistically significant effect in cases of low birth weight, blood transfusion, necrotising enterocolitis, bronchopulmonary dysplasia, and antenatal steroid and surfactant therapies.”

Their hope is that this new information may be useful to ophthalmologists and neonatologists and call their attention to this patient group during screening for ROP.

References

1. Yildirim M, Coban A, Bulut O, Mercül NK, Ince Z. Postnatal weight gain and retinopathy of prematurity in preterm infants: a population-based retrospective cohort study. Matern Fetal Neonatal Med. 2024;37:2337720; doi: 10.1080/14767058.2024.2337720

2. Hellström A, Hård AL, Engström E, et al. Early weight gain predicts retinopathy in preterm infants: new, simple, efficient approach to screening. Pediatrics. 2009;123:e638–e645. doi: 10.1542/peds.2008-2697.

3. Wallace DK, Kylstra JA, Phillips SJ, et al. Poor postnatal weight gain: a risk factor for severe retinopathy of prematurity. J Aapos. 2000;4(:343–347. doi: 10.1067/mpa.2000.110342.

4. Cabañas Poy MJ, Montoro Ronsano JB, Castillo Salinas F, et al. Association between postnatal weight gain and need for treatment in retinopathy of prematurity. J Matern Fetal Neonatal Med. 2022;35:8027–8031. doi: 10.1080/14767058.2021.1940937.

5. Bas AY, Demirel N, Koc E, et al. Incidence, risk factors and severity of retinopathy of prematurity in Turkey (TR-ROP study): a prospective, multicentre study in 69 neonatal intensive care units. Br J Ophthalmol. 2018;102:1711–1716. doi:10.1136/bjophthalmol-2017-311789.