title: Impact of endometriosis on in vitro fertilization and embryo transfer cycles in young women: a stage-dependent interference.
abstract: OBJECTIVE
  Endometriosis is a frequent indication for in vitro fertilization and embryo transfer (IVF-ET). Its influence on IVF-ET cycles remains controversial. We evaluated the impact of the severity of endometriosis on IVF-ET cycles in young women.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Academic tertiary referral centre.
  
  
  METHODS
  In a retrospective cohort analysis, 164 IVF-ET cycles in 148 women with endometriosis-associated infertility were analyzed. Eighty cycles performed during the same period on 72 consecutive women with tubal infertility were considered as controls. All patients were younger than 35 years old.
  
  
  METHODS
  Response to controlled ovarian hyperstimulation (COH), number of oocytes retrieved, fertilization, implantation and pregnancy rate (PR).
  
  
  RESULTS
  Clinical PR was lower in the group with endometriosis (all stages) in comparison with the tubal factor group. Higher total gonadotropin requirements, lower response to COH and lower oocyte yield were also found in the endometriosis group. Stage-stratified analysis showed a lower fertilization rate in stage I-II (52.6% stage I-II, 70.5% stage III-IV and 71.9% tubal factor). In stage III-IV endometriosis there was a higher cycle cancellation rate, a reduced response to COH and a lower PR compared with both the stage I-II and the tubal infertility groups (PR 9.7, 25 and 26.1%, respectively).
  
  
  CONCLUSIONS
  Stage III-IV was strongly associated with poor IVF outcome. A decreased fertilization rate in stage I-II might be a cause of subfertility in these women, owing to a hostile environment caused by the disease.
authors.affiliation: Department of Science for the Woman and Child's Health, University of Florence, Florence, Italy. cocciame@tin.it
authors.forename: Maria Elisabetta
authors.initials: ME
authors.lastname: Coccia
authors.forename: Francesca
authors.initials: F
authors.lastname: Rizzello
authors.forename: Giulia
authors.initials: G
authors.lastname: Mariani
authors.forename: Carlo
authors.initials: C
authors.lastname: Bulletti
authors.forename: Antonio
authors.initials: A
authors.lastname: Palagiano
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Scarselli
mesh_terms: D004624:Embryo Transfer; D004715:Endometriosis / Q000150:complications*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000209:etiology*; D010049:Ovarian Diseases / Q000150:complications*; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies