The influence of gestational age on the dynamic behavior of other risk factors associated with retinopathy of prematurity (ROP)

Abstract

BackgroundImproved survival of preterm neonates has increased the incidence of retinopathy of prematurity (ROP) in many middle-income countries.AimThis study aimed to verify the main risk factors for the development of ROP according to different gestational age (GA) groups.MethodsA prospective cohort study including infants weighing ≤1,500 g or GA ≤32 weeks at birth was conducted. The main clinical outcomes were the occurrence of any stage of ROP and severe ROP. The perinatal variables considered for the study were: birth weight; GA; gender; to be small for GA (SGA); weight gain from birth to the sixth week of life; use of oxygen in mechanical ventilation or nasal CPAP; multiple gestations; therapeutic use of surfactant, indomethacin, and erythropoietin; occurrence of sepsis, meningitis, intraventricular hemorrhage, and patent ductus arteriosus; need for and volume of blood transfusion; and 10-min Apgar score. The patients were divided into three groups according to GA: (group 1) infants of GA ≤28 weeks at birth (n = 100); (group 2) infants of GA = 29–31 weeks at birth (n = 215); and (group 3) infants of GA ≥32 weeks at birth (n = 152).ResultsA total of 467 newborn infants were included. Mean BW and GA in the total cohort were 1,216.5 g (±278.3) and 30.3 weeks (±2.2), respectively. Gestational age groups were not matched for BW and SGA. Any stage of ROP occurred in 111 patients (23.8%) and 24 (5.1%) patients developed severe ROP. Only BW and volume of blood transfusion were significant factors for the occurrence of any stage of ROP in all groups. In group 1, GA, the twin situation, and use of erythropoietin were statistically significant factors. In group 2, only GA and need for blood transfusion were significant. In group 3, use of oxygen in mechanical ventilation, sepsis, and need for blood transfusion were significant for ROP onset. The logistic regression determined that patients in groups 2 and 3 were less likely to develop ROP than patients in group 1.ConclusionsPatients in groups 1 and 2 developed ROP due to general immaturity, whereas bigger babies, of GA ≥32 weeks, developed ROP because they were “sicker” babies with more comorbidities.

Incidence of retinopathy of prematurity in extremely premature infants over an 18‐year period

“…Although there was increased incidence of ROP in males in our study, this was not found to be significant ( P = 0.425). Similar non‐significant differences have been seen in other studies 4,18,26,27 …”

“…Although it is difficult to make direct comparisons between studies in terms of specific incidence of ROP, consistent relationships between variables have been found. Population 5,13–15 and single‐centre studies 25–28 generally agree that with decreased GA and birthweight, there is increased frequency of ROP and increased incidence of severe ROP. Our findings are consistent with these trends, as seen in Figure 2 for birthweight and Table 4 for GA. Logistic regression analyses in this study revealed a strong inverse relationship between advancing GA and risk of development of ROP and severe ROP.…”

Correlation between risk factors during the neonatal period and appearance of retinopathy of prematurity in preterm infants in neonatal intensive care units in Alexandria, Egypt

“…In a prospective cohort study by Fortes Filho et al,24 467 infants weighing ≤ 1500 g or gestational age ≤ 32 weeks at birth were divided into three groups according to gestational age: group 1, comprising infants of gestational age ≤ 28 weeks at birth; group 2, comprising infants of gestational age 29–31 weeks at birth; and group 3, comprising infants of gestational age ≥ 32 weeks at birth. Mean birth weight and gestational age in the total cohort was 1216.5 ± 278.3 g and 30.3 ± 2.2 weeks, respectively.…”

No advanced retinopathy of prematurity stages 4 or 5 in a large high-risk German cohort

“…Moreover, this analysis included every preterm infants who survived until treatment. Some studies only included preterm infants who survived at least 1 year 19 20. The risk for treatment decreased strongly for preterm infants with a GA of >25 weeks.…”