title: Gestational surrogacy in Australia 2004-2011: treatment, pregnancy and birth outcomes.
abstract: BACKGROUND
  Information on gestational surrogacy arrangement and outcomes is limited in Australia.
  
  
  OBJECTIVE
  This national population study investigates the epidemiology of gestational surrogacy arrangement in Australia: treatment procedures, pregnancy and birth outcomes.
  
  
  METHODS
  A retrospective study was conducted of 169 intended parents cycles and 388 gestational carrier cycles in Australia in 2004-2011. Demographics were compared between intended parents and gestational carrier cycles. Pregnancy and birth outcomes were compared by number of embryos transferred.
  
  
  RESULTS
  Over half (54%) intended parents cycles were in women aged <35 years compared to 38% of gestational carrier cycles. About 77% of intended parents cycles were of nulliparous women compared to 29% of gestational carrier cycles. Of the 360 embryo transfer cycles, 91% had cryopreserved embryos transferred and 69% were single-embryo transfer (SET) cycles. The rates of clinical pregnancy and live delivery were 26% and 19%, respectively. There were no differences in rates of clinical pregnancy and live delivery between SET cycles (27% and 19%) and double-embryo transfer (DET) cycles (25% and 19%). Five of 22 deliveries following DET were twin deliveries compared to none of 48 deliveries following SET. There were 73 liveborn babies following gestational surrogacy treatment, including 9 liveborn twins. Of these, 22% (16) were preterm and 14% (10) were low birthweight. Preterm birth was 13% for liveborn babies following SET, lower than the 31% or liveborn babies following DET.
  
  
  CONCLUSIONS
  To avoid adverse outcomes for both carriers and babies, SET should be advocated in all gestational surrogacy arrangements.
authors.affiliation: Faculty of Health, University of Technology Sydney, Broadway, New South Wales, Australia.
authors.forename: Alex Y
authors.initials: AY
authors.lastname: Wang
authors.affiliation: Access Australia, Silverwater, New South Wales, Australia.
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Dill
authors.affiliation: Genea, Sydney, New South Wales, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Bowman
authors.affiliation: Faculty of Health, University of Technology Sydney, Broadway, New South Wales, Australia.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Sullivan
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D015925:Cryopreservation; D004622:Embryo, Mammalian; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D050498:Live Birth; D008875:Middle Aged; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin / Q000706:statistics & numerical data; D047928:Premature Birth / Q000453:epidemiology; D012189:Retrospective Studies; D056826:Single Embryo Transfer / Q000706:statistics & numerical data*; D013533:Gestational Carriers / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: carrier; embryo transfer; gestational surrogacy; intended parents; multiple pregnancy