title: A prospective study of bone density and pregnancy after an extended period of lactation with bone loss.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors: Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor.
authors: M
authors: M
authors: Sowers
authors: J
authors: J
authors: Randolph
authors: B
authors: B
authors: Shapiro
authors: M
authors: M
authors: Jannausch
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density; D005260:Female; D006801:Humans; D007774:Lactation / Q000378:metabolism*; D008137:Longitudinal Studies; D011247:Pregnancy / Q000378:metabolism*; D011446:Prospective Studies; D013997:Time Factors