title: Low-molecular-weight heparin in women with repeated implantation failure.
abstract: Implantation failure is common in assisted reproduction techniques (ART). The role of low-molecular-weight heparin (LMWH) is a matter of debate as a potential factor to improve implantation.
  
  
  OBJECTIVE
  To evaluate the pregnancy rate in patients with or without heparin administration.
  
  
  METHODS
  We performed a retrospective observational analysis of patients with at least two IVF/intracytoplasmic sperm injection cycles with implantation failure, screened for inherited thrombophilia and submitted to further ART cycles with or without administration of LMWH. A total of 265 patients fulfilled the enrollment criteria. Of these 149 (56%) were primary infertile and 116 (44%) were secondary infertile. Their mean age was 36.3 ± 3.6 years. We analyzed basal FSH, smoking habit, gene variants for inherited thrombophilia (i.e., MTHFR C677T, prothrombin G202A10G and Factor V Leiden). The patients underwent 569 new ART cycles: 512 (90%) without and 57 (10%) with LMWH.
  
  
  RESULTS
  In total 105 clinical pregnancies were observed in 569 cycles (18.8%). The pregnancy rate was 17.19% (88/512) in patients not treated with LMWH and 29.52% (17/57) in the LMWH-treated group (p = 0.006). In women over 36 years of age the pregnancy rate was 15.53% (50/322) in nontreated versus 35.71% (10/28) in treated cycles (p = 0.007), while no difference was found in younger women. No statistical difference was found between the presence of inherited thrombophilia and pregnancy rate in treated and untreated cycles.
  
  
  CONCLUSIONS
  significantly higher pregnancy rate in patients with previous ART implantation failures was observed with LMWH. Our results confirm no relation among inherited thrombophilia and pregnancy rate in patients with previous IVF implantation failures. These findings should be confirmed by randomized controlled trials before use of LMWH for ART cycles is recommended.
authors.affiliation: Thrombosis Center, IRCCS Istituto Clinico Humanitas, Milan, Italy.
authors.forename: Corrado
authors.initials: C
authors.lastname: Lodigiani
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Di Micco
authors.forename: Paola
authors.initials: P
authors.lastname: Ferrazzi
authors.forename: Luca
authors.initials: L
authors.lastname: Librè
authors.forename: Veronica
authors.initials: V
authors.lastname: Arfuso
authors.forename: Franco
authors.initials: F
authors.lastname: Polatti
authors.forename: Michela
authors.initials: M
authors.lastname: Benigna
authors.forename: Benigna
authors.initials: B
authors.lastname: Michela
authors.forename: Roberta
authors.initials: R
authors.lastname: Rossini
authors.forename: Emanuela
authors.initials: E
authors.lastname: Morenghi
authors.forename: Lidia
authors.initials: L
authors.lastname: Rota
authors.forename: Benjamin
authors.initials: B
authors.lastname: Brenner
authors.forename: Paolo Emanuele Levi
authors.initials: PE
authors.lastname: Setti
authors.forename: Emanuele Levi Setti
authors.initials: EL
authors.lastname: Paolo
mesh_terms: D003131:Combined Modality Therapy; D010064:Embryo Implantation / Q000187:drug effects*; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage*; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D017211:Treatment Failure
chemical_list: D006495:Heparin, Low-Molecular-Weight