title: Trajectories of maternal sleep problems before and after childbirth: a longitudinal population-based study.
abstract: BACKGROUND
  Sleep problems are common during pregnancy and in the postnatal period, but there is still a lack of longitudinal population-based studies assessing the quantity and quality of sleep in these women. The aim of the current study was to examine the natural development and stability of insomnia and short sleep duration in women from pregnancy to two years postpartum.
  
  
  METHODS
  This was a longitudinal cohort study (the Akershus Birth Cohort Study) of 1480 healthy women, who completed three comprehensive health surveys, at week 32 of pregnancy, week 8 postpartum and year 2 postpartum. The survey was composed of the following validated questionnaires: the Bergen Insomnia Scale, the Pittsburgh Sleep Quality Index and the Edinburgh Postnatal Depression Scale. Differences in sleep characteristics between the three assessment points were compared using Analyses of Variance with repeated measures, and logistic regression analyses were used to examine the stability of sleep variables.
  
  
  RESULTS
  One thousand four hundred and eighty women completed all three surveys, and the mean age at birth was 30.7 (+/-4.9). The prevalence of insomnia remained stable at 60 % at the first two time periods, and remained high at 41 % at year 2 postpartum. The mean sleep duration at the three time periods was 7 h 16 min, 6 h 31 min, and 6 h 52 min, respectively. Concurrent maternal depression could not explain the stability of sleep problems from during and immediately after pregnancy, to sleep problems 2 years postpartum.
  
  
  CONCLUSIONS
  Both insomnia and short sleep duration were found to be very common both before and after pregnancy.
authors.affiliation: Division of Mental Health, Norwegian Institute of Public Health, Kalfarveien 31, 5018, Bergen, Norway. borge.sivertsen@fhi.no.|The Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research Health, Bergen, P.O. Box 7810, N-5020, Bergen, Norway. borge.sivertsen@fhi.no.|Department of Psychiatry, Helse Fonna HF, P.O. Box 2170, N-5504, Haugesund, Norway. borge.sivertsen@fhi.no.
authors.forename: Børge
authors.initials: B
authors.lastname: Sivertsen
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. Mari.Hysing@uni.no.
authors.forename: Mari
authors.initials: M
authors.lastname: Hysing
authors.affiliation: Division of Psychiatry, Stavanger University Hospital, PO Box 8100, Stavanger, NO-4068, Norway. signe.karen.dorheim@sus.no.
authors.forename: Signe K
authors.initials: SK
authors.lastname: Dørheim
authors.affiliation: Division of Mental Health, Norwegian Institute of Public Health, Kalfarveien 31, 5018, Bergen, Norway. Malin.Eberhard.Gran@fhi.no.|Health Services Research Center, Akershus University Hospital, Lørenskog, Norway. Malin.Eberhard.Gran@fhi.no.|Institute of Clinical Medicine, Campus Ahus, University of Oslo, Lørenskog, Norway. Malin.Eberhard.Gran@fhi.no.
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; D058725:Peripartum Period; D049590:Postpartum Period; D011247:Pregnancy; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology* / Q000209:etiology; D011795:Surveys and Questionnaires; D013995:Time