title: Pregnancy-associated transient osteoporosis of the hip: results of a case-control study.
abstract: The etiology and underlying mechanisms of transient of osteoporosis of the hip (TOH) during pregnancy are still unclear, since no systematic analyses exist. Our results support the hypothesis that TOH is a multifactorial disease, which is associated with immobility, dental problems, and lack of exercise in childhood.
  
  
  BACKGROUND
  Pregnancy-associated transient osteoporosis of the hip (TOH) is a rare but severe form of osteoporosis, which may affect a subgroup of women in the last trimester of pregnancy or immediately postpartum. Common symptoms include acute pain of the hip(s) due to bone marrow edema or even hip fractures. The exact underlining mechanisms of this disorder are still unknown since no published systematic analyses exist.
  
  
  METHODS
  Out of a total of 52 TOH patients, 33 TOH patients could be matched with 33 healthy controls according to age, region, and gravity. The aim of this retrospective case-control study was to evaluate the risk factors for TOH in a homogenous population of women.
  
  
  RESULTS
  The baseline characteristics of the two study groups were similar. Overall, 12.1% of the TOH patients sustained a hip fracture. Expectedly, 90.9% of the TOH patients complained about pain of the hip (p ≤ 0.001). TOH patients suffered more frequently from severe dental problems during childhood (p = 0.023) and performed less often sports before and after puberty (p ≤ 0.001), whereas the frequency of immobilization during pregnancy was threefold higher compared to the control group (p = 0.007). We found a significant increase of the TOH risk in patients with dental problems in childhood (OR 3.7; CI 1.3-10.7) as well as in patients with lack of exercise during childhood (OR 4.2; CI 1.3-12.9).
  
  
  CONCLUSIONS
  Our results support the hypothesis that pregnancy-associated TOH is a multifactorial disease, to which several individual factors may contribute. Hereby, we found significant associations with immobility, dental problems, and lack of exercise in childhood.
authors.affiliation: Department of Bone Oncology, Gynecological Endocrinology and Reproductive Medicine, German Reference Centre for Pregnancy-Associated Osteoporosis, Nordwest Hospital Frankfurt, Steinbacher Hohl 2-26, 60488, Frankfurt a. M, Germany. hadji.peyman@khnw.de.|Faculty of Medicine, Philipps-University of Marburg, Marburg, Germany. hadji.peyman@khnw.de.
authors.forename: Peyman
authors.initials: P
authors.lastname: Hadji
authors.affiliation: Department of Obstetrics and Gynecology, Philipps-University of Marburg, Marburg, Germany.
authors.forename: Jelena
authors.initials: J
authors.lastname: Boekhoff
authors.affiliation: Department of Obstetrics and Gynecology, Philipps-University of Marburg, Marburg, Germany.
authors.forename: Melitta
authors.initials: M
authors.lastname: Hahn
authors.affiliation: Faculty of Medicine, Philipps-University of Marburg, Marburg, Germany.|Department of Obstetrics and Gynecology, Vivantes Klinikum Friedrichshain, Berlin, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Hellmeyer
authors.affiliation: Statistical Institute Dr. Hars, Berlin, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Hars
authors.affiliation: Faculty of Medicine, Philipps-University of Marburg, Marburg, Germany.|Department of Obstetrics and Gynecology, Buergerhospital Frankfurt, Goethe-University of Frankfurt, Frankfurt, Germany.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kyvernitakis
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005858:Germany / Q000453:epidemiology; D006620:Hip Fractures / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D010024:Osteoporosis / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D058866:Osteoporotic Fractures / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000517:prevention & control; D012189:Retrospective Studies
keywords: Fracture; Hip; Pregnancy associated osteoporosis; Transient osteoporosis