title: Outcome of monochorionic-biamniotic twins conceived by assisted reproduction: a population-based study.
abstract: Objecive: To evaluate the perinatal outcome of monochorionic-diamniotic twins conceived by assisted reproduction technology (ART).
  
  
  METHODS
  We compared data from a national population-based perinatal registry on perinatal outcomes of monochorionic-diamniotic twins conceived by ART with their dichorionic counterparts and with spontaneous monochorionic-diamniotic twins. We compared maternal characteristics, pregnancy complications and perinatal outcomes.
  
  
  RESULTS
  Monochorionic-diamniotic twin pregnancies (n=45) comprised 5.5% of all ART twins, and 9.3% of all monochorionic twins in this dataset. ART does not appear to increase the already high risk of monochorionicity compared to spontaneous conception, with the latter having an increased incidence for birth weight <1500 g [odds ratio (OD) 2.6, 95% confidence interval (CI) 1.2-5.4].
  
  
  CONCLUSIONS
  Our results disagree with hospital-based data and suggest that monochorionic-diamniotic twins following ART are not at increased risk of adverse perinatal outcomes compared to spontaneous monochorionic-diamniotic twins as well as to dichorionc twins conceived by ART.
authors.forename: Andreja
authors.initials: A
authors.lastname: Trojner Bregar
authors.forename: Isaac
authors.initials: I
authors.lastname: Blickstein
authors.forename: Ivan
authors.initials: I
authors.lastname: Verdenik
authors.forename: Miha
authors.initials: M
authors.lastname: Lucovnik
authors.forename: Natasa
authors.initials: N
authors.lastname: Tul
mesh_terms: D000328:Adult; D000650:Amnion / Q000033:anatomy & histology; D002823:Chorion / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D054238:Perinatal Mortality; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin / Q000706:statistics & numerical data; D012042:Registries; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects; D012307:Risk Factors; D017524:Slovenia / Q000453:epidemiology; D014430:Twins, Monozygotic / Q000706:statistics & numerical data