title: Prolonged low-molecular-weight heparin use during pregnancy and subsequent bone mineral density.
abstract: BACKGROUND
  In contrast to unfractionated heparin (UFH), use of low-molecular weight heparin (LMWH) during pregnancy has not been reported to be associated with a significant decrease in bone mineral density (BMD). The aim of this study was to investigate whether long-term use of LMWH during pregnancy is associated with subsequent decrease in BMD or with increased number of osteoporotic fractures.
  
  
  METHODS
  In this observational cohort study BMD was measured by dual energy X-ray absorptiometry (DEXA) 4-7years after the last delivery in 152 women. Ninety-two women had prolonged LMWH-exposure during pregnancy - 75 as prophylaxis and 17 as treatment for venous thromboembolic event (VTE). Dalteparin and enoxaparin were the LMWH-preparations used. Sixty women without LMWH-exposure served as controls. A questionnaire about lifestyle factors and medical history was filled out by the subjects.
  
  
  RESULTS
  Lumbar spine BMD in the LMWH users was lower than that in the controls both in the prophylactic group (1.22g/cm(2) vs. 1.27g/cm(2); p=0.03), and in the treatment group (1.20g/cm(2) vs. 1.27g/cm(2); p=0.07). BMD in femoral neck did not differ between the LMWH-users and controls. However, after adjusting for potential confounding factors, LMWH-exposure did not remain associated with decreased BMD in lumbar spine. Use of contraceptive pills was positively associated with BMD in lumbar spine. Incidence of osteopenia was 13% in the LMWH-group and 8% in the control-group, (p=0.4). No osteoporosis or osteoporotic fractures were found.
  
  
  CONCLUSIONS
  Prolonged use of LMWH during pregnancy was not associated with subsequent decrease in BMD, osteopenia, osteoporosis, or osteoporotic fractures.
authors.affiliation: University of Helsinki, Helsinki University Hospital, Department of Obstetrics and Gynaecology, Haartmaninkatu 2, 00290 Helsinki, Finland. Electronic address: paivi.galambosi@gmail.com.
authors.forename: Päivi
authors.initials: P
authors.lastname: Galambosi
authors.affiliation: University of Helsinki, Helsinki University Hospital, Department of Obstetrics and Gynaecology, Haartmaninkatu 2, 00290 Helsinki, Finland. Electronic address: hiilesmaa@gmail.com.
authors.forename: Vilho
authors.initials: V
authors.lastname: Hiilesmaa
authors.affiliation: University of Helsinki, Helsinki University Hospital, Department of Obstetrics and Gynaecology, Haartmaninkatu 2, 00290 Helsinki, Finland. Electronic address: veli-matti.ulander@hus.fi.
authors.forename: Veli-Matti
authors.initials: VM
authors.lastname: Ulander
authors.affiliation: University of Helsinki, Helsinki University Hospital, Department of Obstetrics and Gynaecology, Haartmaninkatu 2, 00290 Helsinki, Finland. Electronic address: leena.laitinen@hus.fi.
authors.forename: Leena
authors.initials: L
authors.lastname: Laitinen
authors.affiliation: University of Helsinki, Helsinki University Hospital, Department of Obstetrics and Gynaecology, Haartmaninkatu 2, 00290 Helsinki, Finland. Electronic address: aila.tiitinen@hus.fi.
authors.forename: Aila
authors.initials: A
authors.lastname: Tiitinen
authors.affiliation: University of Turku and Turku University Central Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland. Electronic address: riskaa@utu.fi.
authors.forename: Risto
authors.initials: R
authors.lastname: Kaaja
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D015519:Bone Density / Q000187:drug effects*; D001851:Bone Diseases, Metabolic / Q000139:chemically induced; D015331:Cohort Studies; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D008875:Middle Aged; D010024:Osteoporosis / Q000139:chemically induced; D058866:Osteoporotic Fractures / Q000139:chemically induced; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000517:prevention & control*; D054556:Venous Thromboembolism / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight
keywords: Bone mineral density; Low-molecular-weight heparin; Osteopenia; Osteoporosis; Pregnancy; Risk factors