After three years of accrual and follow-up the incidence of TT-CMV was 0%. Sample size calculations were revised using a 95% confidence interval for a single group of VLBW infants regardless of maternal CMV serostatus. The necessary sample size was 300 transfused VLBW infants based on a one-sided exact 95% confidence interval for a single proportion of 0.0 with an upper bound of 0.01.