title: Dichorionic triplet pregnancies: risk of miscarriage and severe preterm delivery with fetal reduction versus expectant management. Outcomes of a cohort study and systematic review.
abstract: BACKGROUND
  In trichorionic pregnancies, fetal reduction from three to two lowers the risk of severe preterm delivery, but provides no advantage in survival. Similar data for dichorionic triamniotic (DCTA) triplets is not readily available.
  
  
  OBJECTIVE
  To document the natural history of DCTA triplets and the effect of reduction on the risk of miscarriage and severe preterm delivery, compared with expectant management.
  
  
  METHODS
  Systematic search on MEDLINE, EMBASE, and the Cochrane Library.
  
  
  METHODS
  DCTA triplets with three live fetuses at 8-14 weeks of gestation, outcome data with expectant management and/or reduction, miscarriage before 24 weeks of gestation and/or severe preterm delivery before 32-33 weeks of gestation.
  
  
  METHODS
  Five studies were included. Data from these were combined with data from three centres.
  
  
  RESULTS
  There were 331 DCTA triplets. The miscarriage rate was 8.9% (95% CI 5.8-13.3%) and the severe preterm delivery rate was 33.3% (95% CI 27.5-39.7%), with expectant management. The miscarriage rate was 14.5% (95% CI 7.6-26.2%) with a reduction of the monochorionic pair, 8.8% (95% CI 3.0-23.0%) with a reduction of one fetus of the monochorionic pair, and 23.5% (9.6-47.3%) with a reduction of the fetus with a separate placenta. Severe preterm delivery rates were 5.5% (95% CI 1.9-14-9%), 11.8% (95% CI 4.7-26.6%), and 17.6% (95% CI 6.2-41.0%), respectively.
  
  
  CONCLUSIONS
  In DCTA triplets, expectant management is a reasonable choice when the top priority is a liveborn infant. Where the priority is to minimise severe preterm delivery, the most advisable option is fetal reduction. Further studies are needed to clarify which particular technique is advisable to optimise the outcome.
authors: Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's University of London, London, UK.
authors: M
authors: M
authors: Morlando
authors: Queen Charlotte's and Chelsea Hospital, London, UK.
authors: L
authors: L
authors: Ferrara
authors: Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's University of London, London, UK.
authors: F
authors: F
authors: D'Antonio
authors: Queen Charlotte's and Chelsea Hospital, London, UK.
authors: A
authors: A
authors: Lawin-O'Brien
authors: Fetal Medicine Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors: S
authors: S
authors: Sankaran
authors: Fetal Medicine Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.|Division of Women's Health, King's College, London, UK.
authors: D
authors: D
authors: Pasupathy
authors: Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's University of London, London, UK.
authors: A
authors: A
authors: Khalil
authors: Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's University of London, London, UK.
authors: A
authors: A
authors: Papageorghiou
authors: Fetal Medicine Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors: P
authors: P
authors: Kyle
authors: Queen Charlotte's and Chelsea Hospital, London, UK.
authors: C
authors: C
authors: Lees
authors: Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's University of London, London, UK.
authors: B
authors: B
authors: Thilaganathan
authors: Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's University of London, London, UK.
authors: A
authors: A
authors: Bhide
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D008131:London / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D018607:Pregnancy Reduction, Multifetal / Q000706:statistics & numerical data*; D059286:Pregnancy, Triplet / Q000706:statistics & numerical data*; D047928:Premature Birth / Q000453:epidemiology*; D012307:Risk Factors
keywords: Dichorionic triplets; embryo reduction; fetal reduction; mixed chorionicity; selective termination; triplet pregnancy