Parity and total body bone density (TBD) in postpartum women

Calcium metabolism is changed in several ways during pregnancy and lactation. Little is known about the effects of parity on bone density of women in childbearing ages. Total body dual x-ray absorptiometry (DXA) scans (Lunar DPX & DPX-L) were performed on 197 women 2 to 3 weeks after delivery and on 17 nullipara matched by range for race, age, weight, and height. In multivariate analysis TBD showed no change with parity. Weight and ethnicity, but not age, were significant covariates and explained about 30% of the variance of TBD. African American women had higher TBD than white or Hispanic women. Parity n BMI kg/m² (sd) Age yrs (sd) TBD g/cm² (sd) 0 17 24.1 (4.6) 29.3 (5.8) 1.168 (.049) 1 104 25.9 (3.9) 24.9 (4.9) 1.152 (.041) 2 43 27.1 (4.4) 26.7(4.9) 1.160 (.043) ≥ 3 50 27.5 (4.8) 27.6 (4.1) 1.165 (.047) TBD: adjusted for age, weight and race This study found no relationship between TBD and parity.