Bruising at birth: antenatal associations and neonatal outcome of extremely low birth weight infants.

Background: Early studies have identified severe cranial bruising as a risk factor for intraventricular hemorrhage ( IVH) in premature infants but the nature of this association has not been evaluated. Objective: To identify antenatal predictors and associations with neonatal outcome of bruised extremely low birth weight infants. Methods: A cohort study comparing 34 bruised and 116 non-bruised infants ( birth weight <= 1,000 g), delivered in two 'Hadassah' university hospitals in Jerusalem between 2000 and 2004. Bruised patients were divided according to the severity of bruising. A univariate model was first applied to examine the associations of the individual independent variables with the outcome variable, followed with a logistic stepwise regression model, performed for each of the outcome variables. Results: In a stepwise logistic regression on 'Any bruising' and 'Severe bruising', only increasing gestational age and exposure to antenatal steroids prior to delivery maintained a protective association with bruising ( OR = 0.74; 95% CI: 0.58 - 0.94; p = 0.015, OR = 0.38; 95% CI: 0.16 - 0.90; p = 0.028, respectively, for 'Any bruising', and OR = 0.77; 95% CI: 0.59 - 1.01; p = 0.055, OR = 0.29; 95% CI: 0.12 - 0.73; p = 0.008, respectively, for 'Severe bruising'). In a stepwise logistic regression analysis, with 'Any bruising' and 'Severe bruising' as forced-in variables and controlling for gestational age, small for gestational age, Apgar scores, respiratory distress syndrome and pneumothorax, 'Severe bruising', but not 'Any bruising', was found to be associated significantly with severe IVH ( OR = 5.60; 95% CI: 1.86 - 16.82; p = 0.002), whereas both 'Any bruising' and 'Severe bruising' were significantly associated with mortality ( OR = 6.31; 95% CI: 2.37 - 16.83; p = 0.000, OR = 3.33; 95% CI: 1.16 - 9.52; p = 0.025 respectively). Conclusion: Antenatal exposure to steroids and increasing gestational age are associated with a lower incidence of bruising at birth in extremely low birth weight infants. Severe bruising at birth is associated with increased incidence of severe intraventricular hemorrhage and mortality. Copyright (C) 2007 S. Karger AG, Basel.