A prospective study of bone density and pregnancy after an extended period of lactation with bone loss

Obstet Gynecol. 1995 Feb;85(2):285-9. doi: 10.1016/0029-7844(94)00351-D.


Objectives: To determine if pregnancy after an extended period of lactation curtails the recovery of maternal bone mineral density.

Methods: Twenty-five women who fully breast-fed their infants for at least 6 months and had a subsequent pregnancy within 18 months of initiating lactation were studied longitudinally. Twenty controls breast-fed similarly, but had no subsequent pregnancy. The women were healthy, well-nourished, and between 20-40 years old. Bone mineral density was measured by dual x-ray energy absorptiometry at the spine and hip.

Results: Both cases and controls lost bone mineral density with extended lactation. The case group had a bone mineral density recovery comparable to the controls.

Conclusion: Women with the dual calcium demands of extended lactation and a subsequent pregnancy are not at risk for failure of bone recovery to pre-lactation levels.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Bone Density*
  • Female
  • Humans
  • Lactation / metabolism*
  • Longitudinal Studies
  • Pregnancy / metabolism*
  • Prospective Studies
  • Time Factors