The role of blood transfusions and iron intake on retinopathy of prematurity
Introduction
Retinopathy of prematurity (ROP) is a vasoproliferative retinal disorder, which represents the main cause of visual impairment and blindness in preterm infants [1]. A recent Italian multicenter study demonstrated that among infants weighing less than 1250 g, 24% were affected by mild forms (grades 1 and 2) of ROP, and 12% by severe forms (grades 3 and 3+) of ROP [2]. Mild forms generally regress with little or no loss of visual function; however, severe forms can lead to retinal scarring and visual loss in the neonatal period.
The pathogenesis of ROP is not fully known, despite a number of perinatal factors, such as prematurity, low birthweight, respiratory distress syndrome, and prolonged oxygen treatment have been recognized as contributory to the development of this retinal disorder [2]. In recent years, the role of blood transfusions and iron intake as risk factors for ROP has been strongly emphasized [3], [4], but the iron intake by transfusions is not generally taken into account when oral iron supplementation is planned in preterm infants. Otherwise, Brooks et al. [5] recently reported that the limitation of blood transfusion does not affect ROP incidence.
The null hypothesis to be tested was that neither blood transfusion nor iron intake increased the risk of ROP in preterm infants. To assess this possibility, we planned a prospective observational study in which the volume of transfused blood and the amount of iron intake was related to the development of ROP in newborn infants with a birthweight of less than 1250 g.
Section snippets
Methods
Infants who were born between January 1996 and December 1997 and whose birthweight was less than 1250 g were eligible for the study. Exclusion criteria were death within 3 weeks of age, the presence of major congenital malformations, and the absence of parental consent.
For each patient, data regarding birthweight, gestational age, Apgar score, antenatal steroid treatment, erythropoietin (EPO) treatment, age at beginning of iron supplementation, and amount of blood transfusion [volume of packed
Results
After parental consent, 52 infants were enrolled in the study; two had to be excluded due to their death (n=2), and five due to the lack of data. All of remaining 45 infants were subjected to ROP screening. They were divided into group A (n=24) that included newborns without ROP, and group B (n=21) that included newborns with ROP. The highest stage in either eye was stage 1 in 13 infants and stage 2 in eight infants. None of the infants were affected by more severe stages of ROP or underwent
Discussion
The overall incidence of ROP in our infants was 47% (50% in infants with birthweight <1000 g), and all cases were ROP 1–2. The Italian ROP Study Group reported a similar incidence but about half of the cases were ROP 3–3+ [2]. It is difficult to explain the mild severity of ROP in our patients, but it is possible that the moderate frequency of RDS (53%) and the relatively short mean duration of mechanical ventilation (6.0±9.5 days) play a role.
In agreement with previous studies [2], [3], [4],
References (19)
- et al.
High iron status in very low birth weight infants is associated with an increased risk of retinopathy of prematurity
J. Pediatr.
(1997) - et al.
Incidence and evolution of the sub-ependymal intraventricular hemorrhage: a study of infants weighing less than 1500 grams
J. Pediatr.
(1978) Red blood cell transfusion practices in the neonate
Clin. Perinatol.
(1995)- et al.
Nutritional anemias in infancy
Clin. Perinatol.
(1995) - et al.
Ferritin in serum, diagnosis of iron deficiency and overload in infants and children
Blood
(1974) Preventing blindness in premature infants
N. Engl. J. Med.
(1998)Italian multicentre study on retinopathy of prematurity
Eur. J. Pediatr.
(1997)- et al.
Blood transfusion. Iron load and retinopathy of prematurity
Eur. J. Pediatr.
(1997) - et al.
The effect of blood transfusion protocol on retinopathy of prematurity: a prospective randomized study
Pediatrics
(1999)
Cited by (126)
Thresholds for Red Blood Cell Transfusion in Preterm Infants: Evidence to Practice
2023, Clinics in PerinatologyDevelopmental Hematology
2023, Avery's Diseases of the NewbornComparing two different Protocols in Withholding Feeds around time of Packed Red Cell Transfusion and Occurrence of TANEC (Transfusion Associated Necrotizing Enterocolitis) in Preterm Neonates
2024, Research Journal of Pharmacy and TechnologyTherapeutic potential of iron chelators in retinal vascular diseases
2023, International Journal of OphthalmologyChanges to Blood-Sampling Protocol to Reduce the Sampling Amount in Neonatal Intensive Care Units: A Quality Improvement Project
2023, Journal of Clinical MedicineFetal hemoglobin, blood transfusion, and retinopathy of prematurity in preterm infants: An observational, prospective study
2023, Indian Journal of Ophthalmology