title: Consanguineous marriage, prepregnancy maternal characteristics and stillbirth risk: a population-based case-control study.
abstract: BACKGROUND
  Consanguineous marriage is associated with increased risks for congenital anomalies, low birthweight, and other adverse perinatal outcomes. In this population-based, case-control study we investigated the association between consanguineous marriage (first-cousin marriage) and stillbirth risk, using prospectively collected information from prepregnancy visits.
  
  
  METHODS
  From 2007 to 2009, we identified 283 stillbirths (cases) and 2088 randomly selected live control births through prepregnancy visits in rural Golestan, Iran. The associations between consanguinity and prepregnancy maternal characteristics and stillbirth risk were examined using multivariate logistic regression.
  
  
  RESULTS
  The rate of consanguineous marriage was 19.4% among cases and 13.6% among controls. Consanguinity was associated with increased stillbirth risk [odds ratio (OR) 1.53; 95% CI 1.10-2.14]. The association was significantly increased for preterm stillbirth (< 37 gestational weeks) (OR 2.43; 95% CI 1.46-4.04) but not for term stillbirth (≥ 37 weeks) (OR 1.14; 95% CI 0.75-1.74). Low and high maternal age, underweight, obesity, nulliparity, a history of infertility or miscarriage, previous obstetric complications (preeclampsia, preterm delivery, and stillbirth in previous pregnancies) were also associated with increased stillbirth risks.
  
  
  CONCLUSIONS
  Consanguineous marriage is associated with increased risk of stillbirth, particularly preterm stillbirth. Findings for other maternal risk factors for stillbirth in rural Iran are consistent with previously reported findings from high-income countries.
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden.|Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Siavash
authors.initials: S
authors.lastname: Maghsoudlou
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden.
authors.forename: Sven
authors.initials: S
authors.lastname: Cnattingius
authors.affiliation: Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Aarabi
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden.|Clinical Epidemiology and Biostatistics, Örebro University Hospital & Örebro University, Örebro, Sweden.|Research Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Montgomery
authors.affiliation: Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Shahriar
authors.initials: S
authors.lastname: Semnani
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden.|Division of Obstetrics and Gynecology, Department of Women's and Children's Health, Karolinska University Hospital and Institute, Stockholm, Sweden.
authors.forename: Olof
authors.initials: O
authors.lastname: Stephansson
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden.|Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors.forename: Anna-Karin
authors.initials: AK
authors.lastname: Wikström
authors.affiliation: Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.|Clinical Epidemiology Unit & Center for Pharmacoepidemiology, Department of Medicine, Solna, Karolinska Institute, Stockholm, Sweden.
authors.forename: Shahram
authors.initials: S
authors.lastname: Bahmanyar
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003241:Consanguinity; D005260:Female; D005865:Gestational Age; D006801:Humans; D007492:Iran / Q000453:epidemiology; D012307:Risk Factors; D050497:Stillbirth / Q000453:epidemiology* / Q000235:genetics*; D055815:Young Adult
keywords: Adverse pregnancy outcome; Golestan province; Iran; consanguineous marriage; consanguinity; cousin marriage; maternal characteristics; stillbirth