title: Endometriosis and pregnancy complications: a Danish cohort study.
abstract: To study the association between endometriosis and risk of pre-eclampsia, cesarean section, postpartum hemorrhage, preterm birth, and small for gestational age (SGA), in a large Danish birth cohort, while taking fertility treatment into account.
  
  
  
  Population-based study.
  
  
  
  Not applicable.
  
  
  
  A total population of 82,793 singleton pregnancies from the Aarhus Birth Cohort (1989 through 2013); 1,213 women had a diagnosis of endometriosis, affecting 1,719 pregnancies.
  
  
  
  None.
  
  
  
  Pre-eclampsia, cesarean section, postpartum hemorrhage, preterm birth, and SGA.
  
  
  
  Endometriosis was associated with an increased risk of preterm birth (adjusted odds ratio [AOR] 1.67, 95% confidence interval [CI] 1.37-2.05), with the risk being highest for very preterm birth (AOR 1.91, 95% CI 1.16-3.15). Compared with unaffected women, women with endometriosis also had an increased risk of pre-eclampsia (AOR 1.37, 95% CI 1.06-1.77) and cesarean section (AOR 1.83, 95% CI 1.60-2.09). Assisted reproductive technology did not explain these findings. No association was found between endometriosis and postpartum hemorrhage or SGA.
  
  
  
  Women with endometriosis were at increased risk of pre-eclampsia, preterm birth, and cesarean section, irrespective of use of assisted reproductive technology.
authors.affiliation: Perinatal Epidemiology Research Unit, Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark. Electronic address: mariatoelboell@hotmail.com.
authors.forename: Maria Tølbøll
authors.initials: MT
authors.lastname: Glavind
authors.affiliation: Department of Gynecology and Obstetrics, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Axel
authors.initials: A
authors.lastname: Forman
authors.affiliation: Perinatal Epidemiology Research Unit, Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark; Section for Epidemiology, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Linn Håkonsen
authors.initials: LH
authors.lastname: Arendt
authors.affiliation: Department of Pathology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Karsten
authors.initials: K
authors.lastname: Nielsen
authors.affiliation: Perinatal Epidemiology Research Unit, Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Tine Brink
authors.initials: TB
authors.lastname: Henriksen
mesh_terms: D000293:Adolescent; D000328:Adult; D001724:Birth Weight; D002585:Cesarean Section; D003718:Denmark / Q000453:epidemiology; D004715:Endometriosis / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D007247:Infertility, Female / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy*; D006473:Postpartum Hemorrhage / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000175:diagnosis / Q000453:epidemiology*; D011247:Pregnancy; D047928:Premature Birth / Q000175:diagnosis / Q000453:epidemiology*; D012042:Registries; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects*; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: Assisted reproductive technology; cesarean section; endometriosis; pre-eclampsia; preterm birth