Purpose: In this study, the effects of maternal smoking along with other clinical risk factors in developing severe retinopathy of prematurity (ROP) were evaluated.
Design: A case-control study.
Methods: Records of newborn infants with an estimated postmenstrual age of 32 weeks or less (n=86) were reviewed. ROP grading was evaluated in accordance with the International Classification of Retinopathy of Prematurity. Severe ROP was diagnosed when it progressed to stage 3 with plus disease. The factors were first evaluated using a univariate logistic regression analysis between the groups of severe and non-severe ROP, followed by a multivariate logistic regression analysis using STATA version 10 and R version 2.71.
Results: A low birth weight, a long duration of artificial ventilation and oxygen supplementation, presence of chronic lung disease, and absence of maternal smoking were found to be significantly associated with severe ROP in the univariate logistic regression analysis. In the multivariate logistic regression analysis, maternal smoking was revealed as a significant factor independently associated with the incidence of severe ROP.
Conclusions: An inhibitory effect of maternal smoking against developing severe ROP is suggested. The mechanism by which smoking may reduce the incidence of severe ROP needs to be further investigated.