Impact of oral contraceptive on bone metabolism.

Oral contraceptives are used by numerous women very often throughout a prolonged period of time and more and more and more frequently early in life, within the first reproductive years. According to the close relationship between estrogen and bone metabolism, the question of the impact of combined oral contraceptive (COC) on bone needs to be addressed. During adulthood, most studies have reported that COC, even those containing a low dose of ethinyl-estradiol had neutral or possibly beneficial effect on bone health. Use of COC within the perimenopausal years prevents the activation of bone metabolism and the decrease in bone mass. In adolescent girls, the skeletal effect of COC is of greater concern. Recent data suggest that the oral contraception may impede the development of peak bone mass, particularly when started within the teen years. Initiation of COC within the first 3 years after menarche would be a strong determinant of bone mass acquisition impairment. Whether this bone impact is also dependent on the dose of ethinyl-estradiol has not been fully elucidated. To date epidemiological studies did not report association between use of combined oral contraceptive and the risk of fracture.