The association between respiratory tract Ureaplasma urealyticum colonization and severe retinopathy of prematurity in preterm infants ≤1250 g.

AIM: To evaluate the association between respiratory tract Ureaplasma urealyticum (Uu) colonization and development of retinopathy of prematurity (ROP) requiring treatment. METHODS: The infants with birthweight (BW) ≤1250 g born in a third-level neonatal intensive care unit between March 2009 and May 2010 were prospectively identified. Nasopharyngeal swabs for Uu colonization were taken in postnatal first 3 days. Culture-positive patients were reevaluated on the twelfth day by nasopharyngeal swabs for Uu. The primary outcome was to define whether there was an association between respiratory tract Uu colonization and severe ROP requiring treatment. Independent sample's t-test or Mann-Whitney U-test was used to compare continuous variables and Chi-square test or Fisher's exact test for categorical variables. Multivariate (backward) logistic regression analysis was performed to simultaneously measure the influence of the independent variables with ROP as the dependent variable. RESULTS: A total of 25 (12.1%) infants developed severe ROP requiring treatment among 206 infants who underwent ROP screening. Mean BW and gestational age of total cohort were 1013±159 g and 27.9±1.6 weeks, respectively. Multivariate analysis demonstrated that BW (OR: 0.64 (95% Cl 0.47-0.88); P=0.006), duration of mechanical ventilation (OR: 1.17 (95% Cl 1.06-1.28); P=0.001), premature rupture of membrane >18 h (OR: 3.83 (95% Cl 1.2-12.2); P=0.02), and Uu positivity in both cultures (OR: 5.02 (95% Cl 1.8-13.9); P=0.002) were independent risk factors for the development of severe ROP requiring treatment. CONCLUSIONS: Respiratory tract colonization with Uu was independently associated with severe ROP requiring treatment.

Adjusted poor weight gain for birth weight and gestational age as a predictor of severe ROP in VLBW infants.

AIM: To analyze relative weight gain by 2-week intervals up to 6 weeks after birth in order to predict the development of retinopathy of prematurity (ROP) requiring treatment among very low birth weight (BW) infants. METHODS: A prospective study including infants with BW ≤1500 g born in a single tertiary intensive care unit over 1-year period was conducted. Body weight measurements were recorded weekly and relative weight gains (g/kg/day) were calculated. The main outcome was development of ROP requiring treatment. RESULTS: Mean BW and gestational age (GA) of the whole cohort were 1165±223 g and 29.3±2.3 weeks, respectively. Relative weight gain at 2 weeks and 4 weeks postnatal age were significantly lower in infants with severe ROP (P=0.041 and P=0.017, respectively). Relative weight gain at 6 weeks was not different between groups. Infants with severe ROP gained 6.7±4 g/kg/day in the first 4 weeks of life, compared with 9.3±4.5 g/kg/day for those with mild or no ROP. After adjusted for BW and GA in logistic regression poor relative weight gain in the first 4 weeks was found to be related to severe ROP (P=0.015). When all the other risk factors significant for severe ROP were included in the logistic regression poor weight gain did not arise as an independent risk factor. CONCLUSION: Poor postnatal weight gain in the first 4 weeks of life is the end result of several comorbidities rather than being an independent risk factor. Poor weight gain can be an additional predictor of severe ROP in very low BW infants.