title: Cause and risk of stillbirth in twin pregnancies: a retrospective audit.
abstract: BACKGROUND
  The epidemiology of twin pregnancies complicated by stillbirth of one or both fetuses is a scarcely examined area. The risk of perinatal death in twin pregnancies is increased 2-5 times compared to singletons, and the identification of preventable risk factors becomes increasingly important as the number of multiple pregnancies is rising. We report the causes of death in twin pregnancies and their respective risk factors.
  
  
  METHODS
  Twin pregnancies (n = 54) complicated by antepartum or intrapartum stillbirth of one or both twins (n = 68) and twin pregnancies with normal outcome (n = 103) in the counties of Oslo and Akershus, Norway, from 1986 to 1995 were included. The cases were classified and compared to the controls in multiple logistic regression analyses with regard to risk factors.
  
  
  RESULTS
  The risk of stillbirth increased with monochorionicity, non-Western origin and assisted reproduction techniques (ART). The cases could be divided into eight different groups according to the primary diagnosis. The groups did not fit any of the existing cause-of-death classifications used on singleton stillbirths.
  
  
  CONCLUSIONS
  The identification of monochorionic gestation should be made early in pregnancy to designate the level of risk. Assisted reproduction techniques leading to a high incidence of twins should be avoided. Health care professionals in the immigrant population should address the detrimental effects of consanguinity on reproductive outcome. We emphasize the need of a new cause-of-death classification for twin stillbirths.
authors: Laerdal Hospital, and Department of Obstetrics and Gynecology, Rikshospitalet University Clinic, University of Oslo, Norway.
authors: Annelise
authors: A
authors: Skeie
authors: J Frederik
authors: JF
authors: Frøen
authors: Ashild
authors: A
authors: Vege
authors: Babill
authors: B
authors: Stray-Pedersen
mesh_terms: D016022:Case-Control Studies; D005260:Female; D005313:Fetal Death / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D016015:Logistic Models; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple; D012189:Retrospective Studies; D012307:Risk Factors; D014427:Twins