title: Factor V Leiden and prothrombin gene G20210A mutation and in vitro fertilization: prospective cohort study.
abstract: BACKGROUND
  The influence of thrombophilia on fertility and on IVF outcome is very controversial. The objectives of this study were: (i) to compare the prevalence of Factor V Leiden (FVL) and prothrombin gene G20210A mutation (PGM) in women undergoing IVF to women with spontaneous pregnancy; (ii) to compare the IVF outcomes and the risk of complications in FVL and PGM carrier to non-carrier women.
  
  
  METHODS
  From March 2005 to December 2009, a total of 510 women requiring IVF were recruited in a prospective cohort study. A separate population of 490 nulliparous women who conceived naturally was also evaluated as fertile controls. All women were tested for the presence of FVL and PGM.
  
  
  RESULTS
  The prevalence of thrombophilic mutations was the same among women requiring IVF (6.9%) and women with spontaneous pregnancy (6.9%). A total of 480 patients underwent 1105 IVF cycles. There were 30 women carriers (86 IVF cycles) and 450 non-carriers for thrombophilic mutations (1019 IVF cycles). No significant differences in the mean number of oocytes retrieved and the number of good quality embryos transferred were found between the mutation carrier and non-mutation carrier women; likewise the reproductive outcome and the IVF complications were not statistically different between the two groups. The cumulative live birth rate after six IVF cycles was similar in the mutation carrier and non-mutation carrier women. For the mutation carrier women, the optimistic estimate of cumulative live birth rate after six IVF cycles was 60.8% and the conservative estimate was 50.0%. Corresponding rates for the non-mutation carrier women were 56.8 and 36.2%, respectively.
  
  
  CONCLUSIONS
  The results of this study suggest that FVL and PGM presence in asymptomatic women and in the absence of other risk factors do not influence IVF outcome, or represent risk factors for ovarian hyperstimulation syndrome (OHSS), or favour thrombosis after IVF. Screening for FVL and PGM does not appear to be justified to identify the patients at the risk for IVF failure, and/or for OHSS, and/or for thrombotic complications.
authors.affiliation: Assisted Reproduction Unit, Department of Obstetrics and Gynaecology, Institute for Maternal and Child Health IRCCS Burlo Garofolo and University of Trieste, Via dell'Istria, 65/1, 34137 Trieste, Italy. ricci@burlo.trieste.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ricci
authors.forename: Paolo
authors.initials: P
authors.lastname: Bogatti
authors.forename: Leo
authors.initials: L
authors.lastname: Fischer-Tamaro
authors.forename: Elena
authors.initials: E
authors.lastname: Giolo
authors.forename: Stefania
authors.initials: S
authors.lastname: Luppi
authors.forename: Marcella
authors.initials: M
authors.lastname: Montico
authors.forename: Luca
authors.initials: L
authors.lastname: Ronfani
authors.forename: Marcello
authors.initials: M
authors.lastname: Morgutti
mesh_terms: D000328:Adult; D001723:Birth Rate; D015331:Cohort Studies; D005165:Factor V / Q000235:genetics*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006579:Heterozygote; D006801:Humans; D009154:Mutation; D009865:Oocytes / Q000166:cytology; D011247:Pregnancy; D011256:Pregnancy Outcome; D015995:Prevalence; D011446:Prospective Studies; D011516:Prothrombin / Q000235:genetics*; D012306:Risk; D013927:Thrombosis / Q000473:pathology
chemical_list: C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin