Single photon bone densitometer has been used to determine the bone mineralcontents in 1521 cases of mid and late pregnant women. The results showed that thecontents are significantly lower than the normal group（P<0.001）. Varying degrees ofbone mineral loss took place in 488 cases（32.1%） of pregnant women. Serumosteocalcin（BGP） levels in 40 cases of normal nonpregnant women and 41 cases of thebone mineral loss group of pregnant women have been measured simultaneously

Theresults showed that the contents of the bone mineral loss group of pregnant womenare obviously lower than the normal group（P<0.001）. This fact implies that thedeterminations of single photon bone densitometer and serum BGP RIA can be usedas the indices for assessing the bone mineral loss in pregnant women.