title: Interpregnancy interval as a risk factor for postmenopausal osteoporosis.
abstract: OBJECTIVE
  Bone mass loss associated with pregnancy and lactation is usually regained in the postpartum period. However, it is not known whether the bone loss is completely recovered in women with a shortened interpregnancy interval (IPI). The aim of this study was to analyze the effect of IPI and gynecological history on postmenopausal osteoporosis.
  
  
  METHODS
  The study was conducted among 537 postmenopausal women who were divided into two groups in accordance with the osteoporosis status. Prior to bone densitometry, the patients were questioned about reproductive history. Dual-energy X-ray absorptiometry was used to measure lumbar spinal, femur neck and total femoral bone mineral density.
  
  
  METHODS
  Association between IPI and postmenopausal osteoporosis was analyzed.
  
  
  RESULTS
  The comparison of both groups according to the total duration of breastfeeding did not reveal a considerable variation (p=0.288). In the osteoporosis group the age and duration of menopause were found to be significantly higher (p<0.001) whereas the age of first pregnancy and IPI were notably lower in comparison to the controls group (p<0.001). Multivariate logistic regression analyses revealed that women who have 0-12 months interpregnancy interval have the highest risk for osteoporosis (OR: 4.306; 95% CI, 1.684-11.01). This analysis confirmed that the occurrence of first pregnancy under 27 years of age conveyed a higher risk for osteoporosis, as well.
  
  
  CONCLUSIONS
  Shortened IPI may have a detrimental effect on bone mineral density in postmenopausal age.
authors.affiliation: Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey. Electronic address: gulcinsahinmd@gmail.com.
authors.forename: Gulcin
authors.initials: G
authors.lastname: Sahin Ersoy
authors.affiliation: Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Giray
authors.affiliation: Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey.
authors.forename: Seda
authors.initials: S
authors.lastname: Subas
authors.affiliation: Department of Family Medicine, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey.
authors.forename: Ersin
authors.initials: E
authors.lastname: Simsek
authors.affiliation: Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey.
authors.forename: Onder
authors.initials: O
authors.lastname: Sakin
authors.affiliation: Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey.
authors.forename: Omer Talip
authors.initials: OT
authors.lastname: Turhan
authors.affiliation: Department of Obstetrics and Gynecology, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey.
authors.forename: Sadullah
authors.initials: S
authors.lastname: Bulut
mesh_terms: D015502:Absorptiometry, Photon; D015519:Bone Density; D001942:Breast Feeding; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000453:epidemiology* / Q000517:prevention & control; D010298:Parity; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D014421:Turkey / Q000453:epidemiology
keywords: Age at first pregnancy; Bone mineral density; Breast-feeding; Interpregnancy interval; Postmenopausal osteoporosis