title: Childbirth, hospitalisation and sickness absence: a study of female twins.
abstract: OBJECTIVE
  To investigate associations of giving birth with morbidity in terms of hospitalisation and social consequences of morbidity in terms of sickness absence (SA), while taking familial (genetics and shared environmental) factors into account.
  
  
  METHODS
  Prospective register-based cohort study. Estimates of risk of hospitalisation and SA were calculated as HRs with 95% CIs.
  
  
  METHODS
  All female twins, that is, women with a twin sister, born in Sweden.
  
  
  METHODS
  5118 Swedish female twins (women with a twin sister), born during 1959-1990, where at least one in the twin pair had their first childbirth (T0) during 1994-2009 and none gave birth before 1994.
  
  
  METHODS
  Hospitalisation and SA during year 3-5 after first delivery or equivalent.
  
  
  RESULTS
  Preceding the first childbirth, the mean annual number of SA days increased for mothers, and then decreased again. Hospitalisation after T0 was associated with higher HRs of short-term and long-term SA (HR for short-term SA 3.0; 95% CI 2.5 to 3.6 and for long-term SA 2.3; 95% CI 1.6 to 3.2). Hospitalisation both before and after first childbirth was associated with a higher risk of future SA (HR for long-term SA 4.2; 95% CI 2.7 to 6.4). Familial factors influenced the association between hospitalisation and long-term SA, regardless of childbirth status.
  
  
  CONCLUSIONS
  Women giving birth did not have a higher risk for SA than those not giving birth and results indicate a positive health selection into giving birth. Mothers hospitalised before and/or after giving birth had higher risks for future SA, that is, there was a strong association between morbidity and future SA.
authors.affiliation: Division of Insurance Medicine, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Emma
authors.initials: E
authors.lastname: Björkenstam
authors.affiliation: Division of Insurance Medicine, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Alexanderson
authors.affiliation: Division of Insurance Medicine, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Jurgita
authors.initials: J
authors.lastname: Narusyte
authors.affiliation: Division of Insurance Medicine, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Linnea
authors.initials: L
authors.lastname: Kjeldgård
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Annina
authors.initials: A
authors.lastname: Ropponen
authors.affiliation: Division of Insurance Medicine, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Pia
authors.initials: P
authors.lastname: Svedberg
mesh_terms: D000041:Absenteeism; D000293:Adolescent; D000328:Adult; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008875:Middle Aged; D036801:Parturition; D011247:Pregnancy; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D018582:Sick Leave / Q000706:statistics & numerical data*; D013548:Sweden; D055815:Young Adult
keywords: EPIDEMIOLOGY; PUBLIC HEALTH; childbirth; hospitalization; sick leave