title: Insomnia before and after childbirth: The risk of developing postpartum pain-A longitudinal population-based study.
abstract: OBJECTIVE
  To examine if insomnia before and after childbirth predicts the development of postpartum bodily pain.
  
  
  METHODS
  This study is part of a longitudinal cohort study, the Akershus Birth Cohort Study, which targeted all women giving birth at Akershus University Hospital in Norway. The current sample is comprised of 1480 women who participated at all three time points, yielding a participation rate of 32% of the 4662 women who originally consented to participate. The Bergen Insomnia Scale (BIS) was used to measure insomnia and a latent profile analysis (LPA) was used to identify subsets of women who shared a similar pattern of responses on the BIS-scale across the three time points. Pain was measured using the bodily pain scale, derived from the Primary Care Evaluation of Mental Disorders (PRIME-MD) and symptoms of depression were measured by the Edinburgh Postnatal Depression Scale (EPDS).
  
  
  RESULTS
  Using a latent profile analysis a three class model showed the best fit and identified one major group (55.6%) with a low BIS scores across all three time points, one group with intermediate BIS scores (32.9%), and a smaller group (11.5%) with higher BIS scores across all three times. The chronic high insomnia group had a 2.8-fold increased risk of reporting high levels of bodily pain. The chronic intermediate group was associated with a 2.2-fold increased risk of bodily pain at two years postpartum. Adjusting for demographics and lifestyle behaviors did not reduce any of the associations, while adjusting for depression significantly attenuated the associations. Additional adjustment for pain at eight weeks postpartum further reduced the magnitude of the associations, but both chronic intermediate insomnia and chronic high insomnia remained strongly associated with the onset of bodily pain in the fully adjusted models (RR=1.75, 95% CI: 1.37-2.23) and RR=1.63, 95% CI: 1.15-2.32, respectively).
  
  
  CONCLUSIONS
  The high prevalence of insomnia among women during and after childbirth, in combination with the strong prospective association with impaired physical health, emphasizes the importance of adequately identifying, preventing and treating insomnia for this population.
authors.affiliation: Domain for Mental and Physical Health, Norwegian Institute of Public Health, P.O. Box 973 Sentrum, 5808 Bergen, Norway; The Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research Health, Bergen, P.O. Box 7810, N-5020 Bergen, Norway; Department of Psychiatry, Helse Fonna HF, P.O. Box 2170, N-5504 Haugesund, Norway. Electronic address: borge.sivertsen@fhi.no.
authors.forename: Børge
authors.initials: B
authors.lastname: Sivertsen
authors.affiliation: Department of Psychological Medicine, University of Auckland, Auckland 1142, New Zealand.
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Petrie
authors.affiliation: Domain for Mental and Physical Health, Norwegian Institute of Public Health, P.O. Box 973 Sentrum, 5808 Bergen, Norway; The Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research Health, Bergen, P.O. Box 7810, N-5020 Bergen, Norway; Alcohol and Drug Research Western Norway, Stavanger University Hospital, Stavanger, Norway.
authors.forename: Jens Christoffer
authors.initials: JC
authors.lastname: Skogen
authors.affiliation: The Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research Health, Bergen, P.O. Box 7810, N-5020 Bergen, Norway.
authors.forename: Mari
authors.initials: M
authors.lastname: Hysing
authors.affiliation: Domain for Mental and Physical Health, Norwegian Institute of Public Health, P.O. Box 973 Sentrum, 5808 Bergen, Norway; Health Services Research Center, Akershus University Hospital, Lørenskog, Norway; Institute of Clinical Medicine, Campus Ahus, University of Oslo, Lørenskog, Norway.
authors.forename: Malin
authors.initials: M
authors.lastname: Eberhard-Gran
mesh_terms: D000328:Adult; D019052:Depression, Postpartum / Q000453:epidemiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D009664:Norway / Q000453:epidemiology; D010146:Pain / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology*
keywords: Epidemiology; Longitudinal; Pain; Pregnancy; Sleep