Placental weight and placental ratio as predictors of later blood pressurein childhood

Objective A significant inverse relationship between blood pressure and bir th weight is firmly established. This association may be the result of feta l adaptations to an adverse intrauterine environment Further markers of int rauterine growth include the weight of the placenta and the placental ratio (the ratio of placental weight to birth weight). A number of studies sugge st that a decreased placental weight or an elevated placental ratio may be independent risk factors for subsequent high blood pressure. The overall ev idence for this is, however, inconclusive, The purpose of the present study was to clearly define the relationships between placental weight, placenta l ratio and subsequent blood pressure during childhood. Design Prospective cohort study of 2507 singleton children, born at term du ring 1989-1992, Blood pressures were recorded at ages 1, 3 and 6 years, usi ng a semiautomated oscillometric device. Results Inverse relationships existed between both systolic and diastolic b lood pressure and placental weight, adjusted for current weight at ages 1, 3 and 6 years. The relationships between placental weight and systolic bloo d pressure were statistically significant at ages 1 and 3 years. There was no consistent relationship between placental weight and later blood pressur e within birth weight categories. No clinically or statistically significan t association was seen between the placental ratio and either systolic or d iastolic blood pressures at any age. Conclusions Birth weight, rather than placental weight or their ratio, is t he early life factor most importantly related to subsequent blood pressure in childhood. (C) 2001 Lippincott Williams & Wilkins.