Growth pattern and nutritional intake as predictors for retinopathy of prematurity

Abstract: Background: Retinopathy of prematurity (ROP) is a sight-threatening disease that affects extremely preterm and very preterm infants. Approximately 5–10% of infants screened for ROP go on to develop severe ROP that requires treatment. To minimize unnecessary screening procedures, which can be stressful for these fragile infants, it is important to identify new risk factors and predictors that better determine which infants are at high risk for ROP. The objective of this study was to investigate growth pattern (peri- and postnatal weight gain) and nutritional intake as risk factors for severe ROP. Methods: WINROP (Weight, insulin-like growth factor 1, neonatal, retinopathy of prematurity) is a web-based surveillance system that aims to identify infants at high risk of ROP based on their birth weight (BW), gestational age (GA), and postnatal weight gain. In all cohorts that we studied, BW, GA, gender, and maximum ROP stage and ROP treatment were retrospectively retrieved from hospital records. In Paper I, we validated WINROP in a Swedish population-based cohort of extremely preterm infants (born at GA <27 weeks) (n=407). This cohort, called the EXPRESS cohort, was further evaluated in Paper IV in relation to nutritional intake and the correlation with severe ROP. In Paper II, the association between infant weight standard deviation scores (WSDS) at first sign of ROP and ROP requiring treatment was evaluated in a Gothenburg cohort screened for ROP (n=147). In Paper III, the birth weight standard deviations score (BWSDS) was calculated in 5 cohorts (n=2941) that were previously included in WINROP studies; Paper III assessed the impact of low birth weight as a risk factor for severe ROP. Results: WINROP correctly identified 96% (45/47) of infants who required treatment for ROP in an extremely preterm cohort. Low weight (p=0.001) and low WSDS at first detection of ROP (p=0.002) were risk factors for severe ROP. Low BWSDS (p<0.001) was a risk factor for severe ROP for all preterm infants; however, the impact of low BWSDS increased with increasing GA. In addition, low energy intake (p<0.01) during the first four weeks of life was associated with the development of severe ROP (p<0.01). Conclusions: Weight at birth and postnatal weight gain can be useful predictors for severe ROP as can weight at first detection of ROP. In addition, low energy intake during the first four weeks of a preterm infant’s life may be associated with later severe ROP.