Oral contraceptives and bone mineral density: A population-based study

Am J Obstet Gynecol. 2000 Feb;182(2):265-9. doi: 10.1016/s0002-9378(00)70209-2.


Objective: We sought to test the hypothesis that exposure to oral contraceptives protects the skeleton.

Study design: Multiple regression techniques were used to analyze data for a random sample of 710 Australian women (age range, 20-69 years). Bone mineral density was measured at the lumbar spine, proximal femur, whole body, and distal forearm. Oral contraceptive exposure was assessed by a questionnaire.

Results: Women exposed to oral contraceptives had a 3.3% greater mean bone mineral density adjusted for body mass index and age at the lumbar spine (partial r (2) = 0.009; P =.014). Adjusted mean vertebral bone mineral density was 3.3% greater for premenopausal women (partial r (2) = 0.008; P <.05), but the effect did not reach significance among postmenopausal women. Higher bone mineral density was associated with increased duration of exposure, with a mean increase of 3.2% associated with the first 5 years and a further 0.2% with >/=5 years of exposure. No association was detected at other sites.

Conclusion: Exposure to oral contraceptives may be associated with higher lumbar spine bone mineral density.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Age Factors
  • Aged
  • Alcohol Drinking
  • Australia / epidemiology
  • Body Mass Index
  • Bone Density / drug effects*
  • Bone Resorption / epidemiology
  • Bone Resorption / prevention & control*
  • Bone and Bones / drug effects
  • Bone and Bones / physiology*
  • Calcium, Dietary
  • Contraceptives, Oral / pharmacology*
  • Contraceptives, Oral / therapeutic use
  • Female
  • Femur / drug effects
  • Femur / physiology
  • Forearm / physiology
  • Humans
  • Lumbar Vertebrae / drug effects
  • Lumbar Vertebrae / physiology
  • Menopause / physiology
  • Middle Aged
  • Multivariate Analysis
  • Regression Analysis
  • Smoking
  • Surveys and Questionnaires


  • Calcium, Dietary
  • Contraceptives, Oral