Caffeine for Apnea of Prematurity/THE AUTHORS REPLY

However, most of the 5 to 10 percent of birth weight they lose reflects a loss of water from a reservoir that is established in utero and that is mobilized and excreted in response to falling levels of prolactin.2 Caffeine does not affect the secretion of prolactin,3 but it is a diuretic.4 In a baboon model of the respiratory distress syndrome associated with prematurity, caffeine treatment doubled the output of urine during the first day of treatment.5 These data appear to show that caffeine augments the loss of fluid in the first week of life and that the resulting water deficit resolves during the next three weeks. Schmidt et al. report decreased rates of bronchopulmonary dysplasia and a decreased need for closure of patent ductus arteriosus among infants with very low birth weight who were given caffeine for apnea of prematurity. When bronchopulmonary dysplasia is combined with brain injury and severe retinopathy of prematurity, a count of these three common neonatal illnesses strongly predicts the risk of death or survival with neurosensory impairment.3 Nevertheless, we concur with the cautious recommendation of Hand and Noble to await the long-term outcomes of our study, as stated at the end of our first study report.