Maternal pelvic size, measured by dual energy x-ray absorptiometry, predicts infant birthweight

Indicators of infant; birthweight are important because infant birthweight is related to later health outcomes. This study developed and validated new measures of the pelvis from dual energy absorptiometry (DEXA). Predictors of the new measures of maternal pelvic size were examined and the pelvic si ze measures were examined as predictors of infant birthweight. Data were dr awn from a sample of 326 women in Kawaii and their 608 infants. The women w ere 45-60 years old at the time of the DEXA bone scan and when they recalle d the birthweights of their infants. The birthweights were validated with b irth certificate data. The women were participants in the Early Postmenopau sal Interventional Cohort (EPIC) to study the effects of alendronate on bon e density. Questions on birth histories were added to that study. Adolescen t milk consumption and age at menarche were positively associated with the DEXA hip measure, while Asian ethnicity was negatively associated with the hip measure in multiple regression analysis. In multiple regression analysi s, the hip measure, together with infant gender and gestational age predict ed infant birthweight; mother's height, weight, and ethnicity did not add s ignificantly to the model. DEXA provided measures of the pelvis, which vari ed by ethnicity, hormonal and nutritional variables, and which were indicat ors of infant birthweight. (C) 2000 Wiley-Liss, Inc.