The purpose of this study was to measure the bone mineral density of t
he lumbar spine (L(2)-L(4)) in healthy postpartum women following term
delivery, and to evaluate factors associated with bone mineral densit
y. Using dual energy X-ray absorptiometry, the bone mineral density of
the lumbar spine was determined during 1 year in 123 healthy postpart
um Japanese women following term delivery. The mean bone mineral densi
ty of the lumbar spine was 1.007 +/- 0.108 g/cm(2) (range 0.731-1.252
g/cm(2)). Thus, there were wide interindividual differences. Also, thi
s result was in agreement with the peak bone mass previously reported
for other Japanese women. Multiple regression analysis and linear regr
ession analysis showed that weight and body mass index were each signi
ficantly correlated with bone mineral density of the lumbar spine. Age
, parity, height, and baby's birth weight were not contributory.