title: [Clinical analysis of 12,491 cycles treated in embryo transfer program].
abstract: OBJECTIVE
  To analyze the clinical outcomes of patients treated with in vitro fertilization and embryo transfer (IVF-ET) and influence factors of pregnancy rate.
  
  
  METHODS
  We retrospectively analyzed the clinical data of 12,491 cycles, including 6,832 fresh IVF/intracytoplast single sperm injection (ICSI) cycles and 5,659 frozen embryo transfer (FET) cycles from 2005 to 2007.
  
  
  RESULTS
  The clinical pregnancy rate per cycle was 32.99% (2254/6832) in fresh embryo transfer program, and the live birth rate was 25.75% (1394/5413); the early pregnant loss rate was 9.36% (211/2254), and the prenatal defect rate was 1.45% (25/1722). Through analysis of these patients' basic data, we found that the patients' age, causes for infertility, egg retrieval and cycle number affected the pregnancy rate. Using logistic regression method, we found that patients' age was the most important factor affecting pregnancy outcome. In FET cycles, the clinical pregnancy rate was 38.08% (2155/5659), significantly higher than fresh embryo transfer cycles.
  
  
  CONCLUSIONS
  IVF-ET treatment is a safe and effective method for infertility couples. However, the female age and poor ovarian response are the main factors affecting pregnancy rate. Thawed embryo transfer can increase the accumulated pregnancy rate effectively.
authors.affiliation: Reproductive Medical Center, Peking University Third Hospital, Beijing 100083, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Qiao
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Cai-Hong
authors.initials: CH
authors.lastname: Ma
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Lian
authors.forename: Ling
authors.initials: L
authors.lastname: Gao
mesh_terms: D000328:Adult; D000367:Age Factors; D015925:Cryopreservation; D004624:Embryo Transfer / Q000379:methods; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007246:Infertility / Q000628:therapy*; D050498:Live Birth; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010053:Ovary / Q000502:physiology; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011272:Pregnancy, Multiple; D012189:Retrospective Studies; D055815:Young Adult