Abstract
Nelson and Grether (Pediatrics 1995;95:263-269) hypothesize that magnesium sulphate administered to mothers before delivery of very low birth weight ([VLBW] <1500 g) infants reduces their risk of cerebral palsy (CP). This hypothesis is supported by their analysis of retrospective data pertaining to VLBW Californian infants. Although it is an exciting proposition, it needs to be approached with caution. A causal explanation for the observed association needs to be confirmed with a randomized controlled trial of magnesium sulphate in preterm delivery because it is conceivable that the apparently robust association may have resulted from their study design.
