title: Triplets and quadruplets in Switzerland: comparison with singletons, and evolution over the last decade.
abstract: OBJECTIVE
  Main objectives were 1) to determine the incidence of higher multiple births from 1995 to 1998 in Switzerland, and 2) to evaluate neonatal mortality and morbidity. Secondary objectives were 3) to compare the results with those of matched singletons, and 4) to compare the present data to the first Swiss study (1985-1988).
  
  
  METHODS
  Retrospective analysis of maternal and neonatal data obtained from all Swiss hospitals.
  
  
  RESULTS
  The incidence of triplet births was 1/3247 and that of quadruplet births 1/81,186. The median gestational age was 32 5/7 weeks for triplets, and 28 6/7 weeks for quadruplets. The median birth weight was 1665 g for triplets and 1076 g for quadruplets. Perinatal mortality was 6% for triplets and 19% for quadruplets. Respiratory distress syndrome was the major morbidity as diagnosed in 52% of triplets and 81% of quadruplets. A comparison of triplets with matched singletons showed no significant differences in morbidity and mortality. Compared with the first Swiss study, the mortality rate decreased, while the incidence of triplets increased but decreased for quadruplets.
  
  
  CONCLUSIONS
  The incidence of higher-order multiple births in Switzerland dropped for quadruplets in the last decade but has increased for triplets. The mortality and morbidity of triplets is comparable to that of singletons with a similar gestational age.
authors.affiliation: Neonatal Unit, University Hospital, Zurich, Switzerland. Romaine.Arlettaz@fhk.usz.ch
authors.forename: Romaine
authors.initials: R
authors.lastname: Arlettaz
authors.forename: Elena
authors.initials: E
authors.lastname: Paraskevopoulos
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Bucher
mesh_terms: D002585:Cesarean Section; D005260:Female; D005307:Fertilization in Vitro; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D010062:Ovulation Induction; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D011783:Quadruplets; D012127:Respiratory Distress Syndrome, Newborn / Q000453:epidemiology; D020554:Sperm Injections, Intracytoplasmic; D013557:Switzerland; D014310:Triplets