title: Concentration of leukaemia inhibitory factor (LIF) in uterine flushing fluid is highly predictive of embryo implantation.
abstract: BACKGROUND
  There is strong evidence that locally secreted cytokines control the implantation process and can cause implantation failure. Uterine flushing fluids were analysed to determine their concentrations of leukaemia inhibitory factor (LIF) and tumour necrosis factor (TNF).
  
  
  RESULTS
  We began by flushing the uterine cavities of 33 infertile patients on day 26 of two consecutive cycles. The concentrations of LIF (by enzyme-linked immunosorbent assay) and TNF (by bioassay) were significantly correlated during these cycles (r = 0.762, P = 0.0001 and r = 0.822, P = 0.001 respectively) and hence reliable. Then, after a reference flushing of 30 infertile patients, we followed the outcome of their first consecutive cycle of ovarian stimulation, which preceded either IVF or intrauterine insemination. A total of 10 patients became pregnant. The median concentration of LIF was 0 pg/ml (range: 0-177) and of TNF was 0 U/ml (range: 0-6.17) among those who became pregnant, and 203 pg/ml (range: 0-1620) and 2.14 U/ml (range: 0-16) respectively among those who did not. The LIF concentration was significantly lower in the pregnant group (P = 0.0013).
  
  
  CONCLUSIONS
  A low concentration of LIF in the uterine flushing fluid at day 26 was predictive of subsequent implantation. Use of this procedure should increase the number of IVF attempts yielding successful pregnancies and also lead to corrective therapies.
authors.affiliation: INSERM U131, Clamart, France. Ledeenathalie@aol.com
authors.forename: N
authors.initials: N
authors.lastname: Lédée-Bataille
authors.forename: G
authors.initials: G
authors.lastname: Laprée-Delage
authors.forename: J-L
authors.initials: JL
authors.lastname: Taupin
authors.forename: S
authors.initials: S
authors.lastname: Dubanchet
authors.forename: R
authors.initials: R
authors.lastname: Frydman
authors.forename: G
authors.initials: G
authors.lastname: Chaouat
mesh_terms: D000328:Adult; D010064:Embryo Implantation; D005260:Female; D005307:Fertilization in Vitro; D006131:Growth Inhibitors / Q000032:analysis*; D006801:Humans; D007247:Infertility, Female / Q000378:metabolism*; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000032:analysis*; D018587:Oocyte Donation; D010062:Ovulation Induction; D011247:Pregnancy; D011256:Pregnancy Outcome; D007507:Therapeutic Irrigation; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D014599:Uterus / Q000378:metabolism*
chemical_list: D006131:Growth Inhibitors; D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines; D014409:Tumor Necrosis Factor-alpha