Incidence and risk factors for retinopathy of prematurity in a Brazilian reference service

Sao Paulo Med J. 2014;132(2):85-91. doi: 10.1590/1516-3180.2014.1322544.

Abstract

Context and objective: Retinopathy of prematurity (ROP) is a known cause of blindness in which diagnosis and timely treatment can prevent serious harm to the child. This study aimed to evaluate the incidence of ROP and its association with known risk factors.

Design and setting: Longitudinal incidence study in the neonatal intensive care unit (NICU) of Universidade Estadual de Montes Claros.

Methods: Newborns admitted to the NICU with gestational age less than 32 weeks and/or birth weight less than 1,500 grams, were followed up over a two-year period. The assessment and diagnosis of ROP were defined in accordance with a national protocol. The chi-square test or Fisher's exact test were used to determine associations between independent variables and ROP. Analysis on the independent effect of the variables on the results was performed using multiple logistic regression.

Results: The incidence of ROP was 44.5% (95% confidence interval, CI = 35.6-46.1) in the study population. The risk factors associated with the risk of developing the disease were: birth weight less than 1,000 grams (odds ratio, OR = 4.14; 95% CI = 1.34-12.77); gestational age less than 30 weeks (OR = 6.69; 95% CI = 2.10-21.31); use of blood derivatives (OR = 4.14; 95% CI = 2.99-8.99); and presence of sepsis (OR = 1.99; 95% CI = 1.45-2.40).

Conclusions: The incidence of ROP was higher than that found in the literature. The main risk factors were related to extreme prematurity.

TIPO E LOCAL DE ESTUDO:: Estudo longitudinal de incidência na Unidade de Terapia Intensiva Neonatal (UTIN) da Universidade Estadual de Montes Claros.

MÉTODOS:: Foram acompanhados neonatos admitidos na UTIN, com idade gestacional menor que 32 semanas e/ou peso ao nascimento inferior a 1.500 gramas, por um período de dois anos. Avaliação e diagnóstico de ROP foram definidos conforme protocolo nacional. Utilizou-se o teste qui-quadrado ou teste exato de Fisher para determinar a associação entre as variáveis independentes e ROP. A análise do efeito independente das variáveis sobre o resultado (ROP) foi realizada por meio de regressão logística múltipla.

RESULTADOS:: A incidência de ROP foi de 44,5% (intervalo de confiança, IC 95% = 35,6-46,1) entre a população estudada. Os fatores de risco pesquisados que apresentaram relação de risco para o desenvolvimento da doença foram: peso de nascimento menor que 1000 gramas (odds ratio, OR = 4,14; IC 95% = 1,34;12,77), idade gestacional menor que 30 semanas (OR = 6,69; IC 95% = 2,10;21,31), uso de hemoderivados (OR = 4,14; IC 95% = 2,99;8,99) e presença de sepse (OR = 1,99; IC 95% = 1,45;2,40).

CONCLUSÃO:: A incidência de ROP foi maior que a encontrada na literatura. Os principais fatores de risco estão relacionados à prematuridade extrema.

MeSH terms

  • Brazil / epidemiology
  • Female
  • Gestational Age
  • Humans
  • Incidence
  • Infant, Low Birth Weight
  • Infant, Newborn
  • Infant, Premature
  • Intensive Care Units, Neonatal / statistics & numerical data*
  • Logistic Models
  • Male
  • Oxygen Inhalation Therapy
  • Prospective Studies
  • Reference Values
  • Retinopathy of Prematurity / epidemiology*
  • Risk Factors
  • Severity of Illness Index