At 12 months , total body bone mineral content and BMD had increased in the norethindrone acetate plus conjugated equine estrogens group ( bone mineral content +37 g , P < .001 and BMD +0.012 g/cm , P = .05 ) , but not in those receiving norethindrone acetate plus placebo ( bone mineral content P = .19 and BMD P = .95 ) .