{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T14:44:39Z","timestamp":1786977879385,"version":"build-2736575974"},"reference-count":38,"publisher":"Oxford University Press (OUP)","issue":"12","license":[{"start":{"date-parts":[[2011,8,26]],"date-time":"2011-08-26T00:00:00Z","timestamp":1314316800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2011,12,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Despite reported bone loss during pregnancy and lactation, no study has shown deleterious long-term effects of parity or breastfeeding. Studies have shown higher bone mineral density and reduced risk for fracture in parous than in nulliparous women or no effect of parity and breastfeeding, so long-term effects are uncertain. We studied the effect of parity and breastfeeding on risk for hip, wrist and non-vertebral fragility fractures (hip, wrist, or proximal humerus) in 4681 postmenopausal women aged 50 to 94 years in the Troms\u00f8 Study from 1994\u201395 to 2010, using Cox's proportional hazard models. During 51 906 person-years, and a median of 14.5 years follow-up, 442, 621, and 1105 of 4681 women suffered incident hip, wrist, and fragility fractures, and the fracture rates were 7.8, 11.4, and 21.3 per 1000 person-years, respectively. The risk for hip, wrist, and fragility fracture did not differ between parous (n\u2009=\u20094230, 90.4%) and nulliparous women (n\u2009=\u2009451, 9.6%). Compared with women who did not breast-feed after birth (n\u2009=\u2009184, 4.9%), those who breastfed (n\u2009=\u20093564, 95.1%) had 50% lower risk for hip fracture (HR 0.50; 95% CI 0.32 to 0.78), and 27% lower risk for fragility fracture (HR 0.73; 95% CI 0.54 to 0.99), but similar risk for wrist fracture, after adjustment for age, BMI, height, physical activity, smoking, a history of diabetes, previous fracture of hip or wrist, use of hormone replacement therapy, and length of education. Each 10 months longer total duration of breastfeeding reduced the age-adjusted risk for hip fracture by 12% (HR 0.88; 95% CI 0.78 to 0.99, p for trend\u2009=\u20090.03) before, and marginally after, adjustment for BMI and other covariates (HR 0.91; 95% CI 0.80 to 1.04). In conclusion, this data indicates that pregnancy and breastfeeding has no long-term deleterious effect on bone fragility and fractures, and that breastfeeding may contribute to a reduced risk for hip fracture after menopause. \u00a9 2011 American Society for Bone and Mineral Research<\/jats:p>","DOI":"10.1002\/jbmr.496","type":"journal-article","created":{"date-parts":[[2011,8,31]],"date-time":"2011-08-31T23:43:54Z","timestamp":1314834234000},"page":"2843-2850","source":"Crossref","is-referenced-by-count":53,"title":["Breastfeeding protects against hip fracture in postmenopausal women: The Troms\u00f8 study"],"prefix":"10.1093","volume":"26","author":[{"given":"\u00c5shild","family":"Bj\u00f8rnerem","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynecology, University Hospital of North Norway, Troms\u00f8, Norway"},{"name":"Department of Clinical Medicine, University of Troms\u00f8, Troms\u00f8, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luai A","family":"Ahmed","sequence":"additional","affiliation":[{"name":"Department of Health and Care Sciences, University of Troms\u00f8, Troms\u00f8, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lone","family":"J\u00f8rgensen","sequence":"additional","affiliation":[{"name":"Department of Community Medicine, University of Troms\u00f8, Troms\u00f8, Norway"},{"name":"Department of Health and Care Sciences, University of Troms\u00f8, Troms\u00f8, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jan","family":"St\u00f8rmer","sequence":"additional","affiliation":[{"name":"Department of Radiology, University Hospital North Norway, Troms\u00f8, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ragnar M","family":"Joakimsen","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, University Hospital North Norway, Troms\u00f8, Norway"},{"name":"Department of Clinical Medicine, University of Troms\u00f8, Troms\u00f8, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2011,8,26]]},"reference":[{"key":"2024020804161975600_bib1","doi-asserted-by":"crossref","first-page":"1761","DOI":"10.1016\/S0140-6736(02)08657-9","article-title":"Epidemiology and outcomes of osteoporotic fractures","volume":"359","author":"Cummings","year":"2002","journal-title":"Lancet."},{"key":"2024020804161975600_bib2","doi-asserted-by":"crossref","first-page":"1237","DOI":"10.1359\/jbmr.2002.17.7.1237","article-title":"International variations in hip fracture probabilities: implications for risk assessment","volume":"17","author":"Kanis","year":"2002","journal-title":"J Bone Miner Res."},{"key":"2024020804161975600_bib3","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1016\/S8756-3282(01)00603-2","article-title":"Epidemiology of hip fractures in Oslo, Norway","volume":"29","author":"Lofthus","year":"2001","journal-title":"Bone."},{"key":"2024020804161975600_bib4","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1530\/EJE-07-0032","article-title":"A prospective study of sex steroids, sex hormone-binding globulin, and non-vertebral fractures in women and men: the Troms\u00f8 Study","volume":"157","author":"Bj\u00f8rnerem","year":"2007","journal-title":"Eur J Endocrinol."},{"key":"2024020804161975600_bib5","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1093\/aje\/kwi258","article-title":"Longitudinal changes in forearm bone mineral density in women and men aged 25\u201344 years: the Troms\u00f8 study: a population-based study","volume":"162","author":"Emaus","year":"2005","journal-title":"Am J Epidemiol."},{"key":"2024020804161975600_bib6","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1007\/s10911-005-5394-0","article-title":"Calcium and bone metabolism during pregnancy and lactation","volume":"10","author":"Kovacs","year":"2005","journal-title":"J Mammary Gland Biol Neoplasia."},{"key":"2024020804161975600_bib7","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1138\/20070268","article-title":"Conversations between breast and bone: physiological bone loss during lactation as evolutionary template for osteolysis in breast cancer and pathological bone loss after menopause","volume":"4","author":"Wysolmerski","year":"2007","journal-title":"BoneKEy."},{"key":"2024020804161975600_bib8","doi-asserted-by":"crossref","first-page":"828","DOI":"10.1007\/s001980170033","article-title":"Pregnancy and lactation confer reversible bone loss in humans","volume":"12","author":"Karlsson","year":"2001","journal-title":"Osteoporos Int."},{"key":"2024020804161975600_bib9","doi-asserted-by":"crossref","first-page":"1052","DOI":"10.1002\/jbmr.5650110803","article-title":"Pregnancy and lactation as risk factors for subsequent bone loss and osteoporosis","volume":"11","author":"Sowers","year":"1996","journal-title":"J Bone Miner Res."},{"key":"2024020804161975600_bib10","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1385\/ENDO:17:1:49","article-title":"Bone mineral changes during pregnancy and lactation","volume":"17","author":"Kalkwarf","year":"2002","journal-title":"Endocrine."},{"key":"2024020804161975600_bib11","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1016\/S8756-3282(03)00017-6","article-title":"Longitudinal changes in bone mineral density during normal pregnancy","volume":"32","author":"Kaur","year":"2003","journal-title":"Bone."},{"key":"2024020804161975600_bib12","doi-asserted-by":"crossref","first-page":"570","DOI":"10.1016\/j.bone.2003.11.005","article-title":"Recovery of pregnancy mediated bone loss during lactation","volume":"34","author":"Pearson","year":"2004","journal-title":"Bone."},{"key":"2024020804161975600_bib13","doi-asserted-by":"crossref","first-page":"732","DOI":"10.1007\/s001980170048","article-title":"The effects of pregnancy and lactation on bone mineral density","volume":"12","author":"More","year":"2001","journal-title":"Osteoporos Int."},{"key":"2024020804161975600_bib14","article-title":"Changes in bone mineral density and body composition during pregnancy and postpartum. A controlled cohort study","author":"M\u00f8ller","year":"2011","journal-title":"Osteoporos Int."},{"key":"2024020804161975600_bib15","doi-asserted-by":"crossref","first-page":"3130","DOI":"10.1001\/jama.1993.03500240074029","article-title":"Changes in bone density with lactation","volume":"269","author":"Sowers","year":"1993","journal-title":"JAMA."},{"key":"2024020804161975600_bib16","first-page":"52","article-title":"Bone mineral changes during and after lactation","volume":"94","author":"Polatti","year":"1999","journal-title":"Obstet Gynecol."},{"key":"2024020804161975600_bib17","first-page":"608","article-title":"Bone mineral changes during and after lactation","volume":"94","author":"Laskey","year":"1999","journal-title":"Obstet Gynecol."},{"key":"2024020804161975600_bib18","doi-asserted-by":"crossref","first-page":"893","DOI":"10.1359\/jbmr.2003.18.5.893","article-title":"Nulliparity and fracture risk in older women: the study of osteoporotic fractures","volume":"18","author":"Hillier","year":"2003","journal-title":"J Bone Miner Res."},{"key":"2024020804161975600_bib19","first-page":"2709","article-title":"Effects of estrogen exposure and reproductive factors on bone mineral density and osteoporotic fractures","volume":"80","author":"Nguyen","year":"1995","journal-title":"J Clin Endocrinol Metab."},{"key":"2024020804161975600_bib20","doi-asserted-by":"crossref","first-page":"1166","DOI":"10.1093\/aje\/153.12.1166","article-title":"Influence of parity and lactation on hip fracture risk","volume":"153","author":"Michaelsson","year":"2001","journal-title":"Am J Epidemiol."},{"key":"2024020804161975600_bib21","doi-asserted-by":"crossref","first-page":"808","DOI":"10.1089\/jwh.2005.14.808","article-title":"Menstrual and reproductive factors and fracture risk: the Leisure World Cohort Study","volume":"14","author":"Paganini-Hill","year":"2005","journal-title":"J Women's Health."},{"key":"2024020804161975600_bib22","doi-asserted-by":"crossref","first-page":"851","DOI":"10.1111\/j.1471-0528.2005.00571.x","article-title":"Female reproductive history and the skeleton\u2014a review","volume":"112","author":"Karlsson","year":"2005","journal-title":"BJOG."},{"key":"2024020804161975600_bib23","doi-asserted-by":"crossref","first-page":"684","DOI":"10.1093\/ije\/22.4.684","article-title":"Breastfeeding and other reproductive factors and the risk of hip fractures in elderly women","volume":"22","author":"Cumming","year":"1993","journal-title":"Int J Epidemiol."},{"key":"2024020804161975600_bib24","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1007\/BF01623672","article-title":"Parity, lactation and hip fracture","volume":"3","author":"Hoffman","year":"1993","journal-title":"Osteoporos Int."},{"key":"2024020804161975600_bib25","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1093\/oxfordjournals.aje.a114384","article-title":"Reproductive history and postmenopausal risk of hip and forearm fracture","volume":"124","author":"Alderman","year":"1986","journal-title":"Am J Epidemiol."},{"key":"2024020804161975600_bib26","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1093\/aje\/153.5.465","article-title":"Forearm bone mineral density by age in 7,620 men and women: the Troms\u00f8 study, a population-based study","volume":"153","author":"Berntsen","year":"2001","journal-title":"Am J Epidemiol."},{"key":"2024020804161975600_bib27","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1007\/s10654-009-9333-z","article-title":"Bone mineral density at the hip in Norwegian women and men\u2014prevalence of osteoporosis depends on chosen references: the Troms\u00f8 Study","volume":"24","author":"Emaus","year":"2009","journal-title":"Eur J Epidemiol."},{"key":"2024020804161975600_bib28","article-title":"Cohort profile: the Tromso Study","author":"Jacobsen","year":"2011","journal-title":"Int J Epidemiol. [Internet]."},{"key":"2024020804161975600_bib29","doi-asserted-by":"crossref","first-page":"1001","DOI":"10.1007\/s001980170008","article-title":"The Troms\u00f8 study: registration of fractures, how good are self-reports, a computerized radiographic register and a discharge register?","volume":"12","author":"Joakimsen","year":"2001","journal-title":"Osteoporos Int."},{"key":"2024020804161975600_bib30","doi-asserted-by":"crossref","first-page":"1104","DOI":"10.1016\/S0895-4356(00)00234-1","article-title":"The Troms\u00f8 Study: determinants of precision in bone densitometry","volume":"53","author":"Berntsen","year":"2000","journal-title":"J Clin Epidemiol."},{"key":"2024020804161975600_bib31","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1007\/s001980050088","article-title":"The Troms\u00f8 Study: body height, body mass index and fractures","volume":"8","author":"Joakimsen","year":"1998","journal-title":"Osteoporos Int."},{"key":"2024020804161975600_bib32","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.1359\/jbmr.1998.13.7.1149","article-title":"The Troms\u00f8 Study: physical activity and the incidence of fractures in a middle-aged population","volume":"13","author":"Joakimsen","year":"1998","journal-title":"J Bone Miner Res."},{"key":"2024020804161975600_bib33","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1007\/BF01623377","article-title":"Influence of breastfeeding and other reproductive factors on bone mass later in life","volume":"3","author":"Melton","year":"1993","journal-title":"Osteoporos Int."},{"key":"2024020804161975600_bib34","doi-asserted-by":"crossref","first-page":"901","DOI":"10.1002\/jbmr.5650080802","article-title":"Reproductive correlates of bone mass in elderly women. Study of Osteoporotic Fractures Research Group","volume":"8","author":"Fox","year":"1993","journal-title":"J Bone Miner Res."},{"key":"2024020804161975600_bib35","doi-asserted-by":"crossref","first-page":"1052","DOI":"10.1093\/oxfordjournals.aje.a116570","article-title":"Pregnancy and lactation as determinants of bone mineral density in postmenopausal women","volume":"136","author":"Kritz-Silverstein","year":"1992","journal-title":"Am J Epidemiol."},{"key":"2024020804161975600_bib36","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1007\/BF01623063","article-title":"Parity and bone mineral density in middle-aged women","volume":"4","author":"Murphy","year":"1994","journal-title":"Osteoporos Int."},{"key":"2024020804161975600_bib37","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1001\/archpedi.158.7.650","article-title":"Lactation among adolescent mothers and subsequent bone mineral density","volume":"158","author":"Chantry","year":"2004","journal-title":"Arch Pediatr Adolesc Med."},{"key":"2024020804161975600_bib38","doi-asserted-by":"crossref","first-page":"1969","DOI":"10.1007\/s00198-005-1978-1","article-title":"High parity is associated with increased bone size and strength","volume":"16","author":"Specker","year":"2005","journal-title":"Osteoporos Int."}],"container-title":["Journal of Bone and Mineral Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fjbmr.496","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/academic.oup.com\/jbmr\/article-pdf\/26\/12\/2843\/56557630\/496_ftp.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jbmr\/article-pdf\/26\/12\/2843\/56557630\/496_ftp.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,3,13]],"date-time":"2024-03-13T10:48:01Z","timestamp":1710326881000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jbmr\/article\/26\/12\/2843-2850\/7597899"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,8,26]]},"references-count":38,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2011,8,26]]},"published-print":{"date-parts":[[2011,12,1]]}},"URL":"https:\/\/doi.org\/10.1002\/jbmr.496","relation":{},"ISSN":["0884-0431","1523-4681"],"issn-type":[{"value":"0884-0431","type":"print"},{"value":"1523-4681","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2011,12,1]]},"published":{"date-parts":[[2011,8,26]]}}}