title: Three hundred and thirty cycles of preimplantation genetic diagnosis for serious genetic disease: clinical considerations affecting outcome.
abstract: OBJECTIVE
  To report on our experience with preimplantation genetic diagnosis (PGD) cycles performed for serious genetic disease in relation to the clinical factors affecting outcome.
  
  
  METHODS
  Retrospective review of data from a single centre.
  
  
  METHODS
  Tertiary referral PGD centre in a London teaching hospital.
  
  
  METHODS
  The PGD cycles included 172 cycles for chromosome rearrangements, 96 cycles for single-gene disorders and 62 cycles for X-linked disorders. In vitro fertilisation was the preferred method in chromosome rearrangement and X-linked cases, while intra cytoplasmic sperm injection was used in all single-gene disorders. Appropriate in situ hybridisation fluorescence probes were used in chromosome rearrangement and X-linked cases and polymerase chain reaction was used in single-gene disorders. All pregnancies were followed till delivery.
  
  
  METHODS
  Live birth rate per PGD cycle started.
  
  
  RESULTS
  Eighty-six percent of cycles started (283) reached oocyte retrieval and 3743 eggs were collected, of which 2086 fertilised normally (55.7%). Two hundred and fifty cycles (76%) had embryos sutiable for biopsy on day 3 of in vitro culture, 1714 embryos were biopsied, and in 205 cycles (62%), there was at least one unaffected embryo available for transfer, resulting in 90 pregnancies, 68 clinical pregnancies and 58 live birth. The live birth rate was 18% per cycle started, 21% per egg retrieval and 28% per embryo transfer which significantly affected the live birth outcome. Woman age, number of eggs collected and achieving cryopreservation of surplus embryos had no statistically significant effect on treatment outcome.
  
  
  CONCLUSIONS
  The live birth outcome of PGD cycles for serious genetic disorder is modest and is affected by the number of embryos genetically suitable for transfer.
authors.affiliation: Centre for Preimplantation Genetic Diagnosis, Guy's and St Thomas' Foundation Trust, Guy's Hospital, London, UK. jan.grace@gstt.nhs.uk
authors.forename: J
authors.initials: J
authors.lastname: Grace
authors.forename: T
authors.initials: T
authors.lastname: El-Toukhy
authors.forename: P
authors.initials: P
authors.lastname: Scriven
authors.forename: C
authors.initials: C
authors.lastname: Ogilvie
authors.forename: S
authors.initials: S
authors.lastname: Pickering
authors.forename: A
authors.initials: A
authors.lastname: Lashwood
authors.forename: F
authors.initials: F
authors.lastname: Flinter
authors.forename: Y
authors.initials: Y
authors.lastname: Khalaf
authors.forename: P
authors.initials: P
authors.lastname: Braude
mesh_terms: D000328:Adult; D005260:Female; D030342:Genetic Diseases, Inborn / Q000175:diagnosis*; D006801:Humans; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D019836:Preimplantation Diagnosis / Q000379:methods*; D027724:Reproductive Techniques, Assisted; D012189:Retrospective Studies; D012307:Risk Factors