title: Spontaneous reduction before 12 weeks' gestation and selective reduction similarly extend time to delivery in in vitro fertilization of trichorionic-triamniotic triplets.
abstract: OBJECTIVE
  To determine the prevalence and the relative benefits conferred by selective and spontaneous reduction of one or more fetuses in trichorionic triamniotic triplet pregnancies on time to delivery.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  IVF patients with trichorionic triamniotic triplets between January 1998 and December 2007.
  
  
  METHODS
  None.
  
  
  METHODS
  Gestational length at time of delivery.
  
  
  RESULTS
  Selective reduction to twins was used in 87 of the 153 (56.9%) triplet pregnancies that did not spontaneously reduce prior to <12 weeks, and was associated with longer gestation (13.9 days) with a fourfold greater likelihood of delivery at ≥ 34 weeks' gestation (odds ratio [OR], 4.3; 95% confidence interval [CI] = 2.2-8.6), compared with pregnancies not undergoing selective reduction. Compared with ongoing triplets, spontaneous reduction at <12 weeks' gestation (28 cases) was associated with longer gestation (13.7 days) and significantly greater likelihood delivering at or after 34 weeks' gestation (OR, 3.7; 95% CI, 1.4-9.9).
  
  
  CONCLUSIONS
  Selective reduction of one fetus was used in 56.9% of patients in this population. Early spontaneous reduction (<12 weeks) and selective reduction to twins each conferred similar benefits by extending time to delivery and increasing the likelihood of delivery at or after 34 weeks' gestation.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Christine C
authors.initials: CC
authors.lastname: Skiadas
authors.forename: Stacey A
authors.initials: SA
authors.lastname: Missmer
authors.forename: Carol B
authors.initials: CB
authors.lastname: Benson
authors.forename: David
authors.initials: D
authors.lastname: Acker
authors.forename: Catherine
authors.initials: C
authors.lastname: Racowsky
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000503:physiopathology; D000328:Adult; D000465:Algorithms; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000706:statistics & numerical data; D005260:Female; D005307:Fertilization in Vitro / Q000706:statistics & numerical data; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D018607:Pregnancy Reduction, Multifetal / Q000534:rehabilitation / Q000706:statistics & numerical data; D011261:Pregnancy Trimester, First / Q000502:physiology; D011272:Pregnancy, Multiple / Q000502:physiology* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013997:Time Factors; D014310:Triplets / Q000502:physiology; D014429:Twins, Dizygotic / Q000502:physiology