OBJECTIVETo investigate the prevalence and the risk factors of retinopathy of prematurity (ROP).

METHODSTotally 172 premature infants who were less than 37 weeks postconceptional age, or more than 37 weeks but weighing < 2 500 g at birth, and born at PUMC hospital from May 1, 2003 to November 30, 2004, were enrolled in this study. Their fundus were routinely checked. Diagnosis and staging of ROP were performed according to the international guidelines. Another 20 mature infants were selected as the control group.

RESULTSTwelve infants quitted the treatment or died. The remaining 160 infants completed the follow up. The prevalence of ROP in the premature group was 19.4%, while no ROP was found in the control group. The prevalence of ROP in subgroup with body weight < or = 2 000 g (28.4%) was significantly higher than in subgroup with body weight > 2 000 g (8.3%, chi2 = 10.217, P = 0.001) at birth. The prevalence of ROP in subgroup with postconceptional age < or = 32 weeks (42.5%) was significantly higher than in subgroup with postconceptional age > 32 weeks (11.7%, chi2 = 18.258, P = 0.000). The postconceptional age (OR = 0.959, P = 0.036) and body weight (OR = 0.999, P = 0.026) were the most important risk factors of ROP. Furthermore, blood transfusion ( OR = 0.076, P = 0.029) and Apgar score ( OR = 23.62, P = 0.012) were inversely correlated with ROP. Correlation was not found between ROP prevalence and oxygen inhalation mode, surface active substance, administration of dopamine and dexamethasone, and mother conditions.

CONCLUSIONSThe prevalence of ROP is higher in premature infants than in mature infants. Shorter postconceptional age and lower body weight may result in higher ROP incidence. Routine screening of fundus in premature infants may be helpful for the early detection of ROP.