Is blood pressure inversely related to birth weight? The strength of evidence from a systematic review of the literature.

To assess the strength of evidence for an inverse relationship between blood pressure and birth weight. A systematic review of the published literature. Published studies describing the relationship between blood pressure and birth weight since 1956. More than 66,000 subjects aged 0-71 years. Thirty-four studies described the relationship of blood pressure with birth weight. The majority of the studies of children and adults showed that blood pressure fell with increasing birth weight. Studies of adolescents were inconsistent. In neonates there was a positive relationship between blood pressure and birth weight. The pattern with age was supported by the limited number of studies with repeated measures and was dependent neither on the method of analysis nor on work from a single academic group or country. Blood pressure is inversely related to birth weight in children and in adults. The positive results in neonates and the inconsistency in adolescence may be related to the unusual growth dynamics during these phases of growth. Further studies should concentrate on the mechanisms which underlie the relationship.