title: Co-twin prognosis after single fetal death: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To perform a systematic review and meta-analysis of the effects on the surviving twin of single fetal death comparing monochorionic to dichorionic twins to report the rates of co-twin death, preterm delivery, and neurologic morbidity in the surviving fetus.
  
  
  METHODS
  MEDLINE (inception-December 2010), EMBASE (inception-December 2010), The Cochrane library (inception-December 2010), Web of Science (inception-December 2010), and British Nursing Index (inception-December 2010) were searched electronically.
  
  
  METHODS
  Selected studies had more than five cases of single fetal death with reports of co-twin death, neurologic morbidity, or both co-twin death and neurologic morbidity. They also must have defined the gestational age of single fetal death and chorionicity.
  
  
  RESULTS
  The search yielded 1,386 citations. Full manuscripts were retrieved for 204 and 22 were included in the review and meta-analysis. Twenty manuscripts were used to calculate overall summary statistics for monochorionic and dichorionic twins showing rates of co-twin death after single fetal death (15% compared with 3%), rates of preterm delivery after single fetal death (68% compared with 54%), the rate of abnormal postnatal cranial imaging after single fetal death (34% compared with 16%), and the rate of neurodevelopmental impairment after single fetal death (26% compared with 2%). Odds ratios (ORs) were calculated from 16 manuscripts. There was no significant difference reported between preterm delivery of monochorionic or dichorionic twins (OR 1.1, 95% confidence interval [CI] 0.34-3.51, P=.9). After single fetal death, monochorionic twins had higher odds of an abnormal cranial imaging after delivery, this was not significant (OR 3.25, 95% CI 0.66-16.1, P=.12). After single fetal death, monochorionic twins were 4.81-times more likely to have neurodevelopmental morbidity (95% CI 1.39-16.6, P<.05).
  
  
  CONCLUSIONS
  Monochorionic twins are at significantly increased odds of co-twin demise and neurodevelopmental morbidity after single fetal death.
authors.affiliation: School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Hillman
authors.forename: Rachel K
authors.initials: RK
authors.lastname: Morris
authors.forename: Mark D
authors.initials: MD
authors.lastname: Kilby
mesh_terms: D005060:Europe / Q000453:epidemiology; D005260:Female; D005313:Fetal Death / Q000453:epidemiology*; D005865:Gestational Age; D006801:Humans; D009421:Nervous System Malformations / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011379:Prognosis; D014427:Twins