title: [Uterine contractions at the time of embryo transfer: a hindrance to implantation?].
abstract: OBJECTIVE
  To investigate the hormonal control and the possible consequences of uterine contractions (UC) on IVF-ET outcome.
  
  
  METHODS
  We studied prospectively 220 controlled ovarian hyperstimulation (COH) cycles for IVF-ET. Just before ET, women underwent 5-minute digital recordings of the uterus using US image analysis software for UC assessment. Plasma progesterone (P) and estradiol were measured. Four groups were defined according to UC frequency: < or = 3.0 (n = 53), 3.1 to 4.0 (n = 50), 4.1 to 5.0 (n = 43), and > 5.0 (n = 74) UC/minute, respectively.
  
  
  RESULTS
  Patients, COH and embryology characteristics were comparable in all groups. Notwithstanding estradiol levels were not associated with UC characteristics, plasma P and UC frequency were negatively correlated (r = -0.34, P < 0.001). A stepwise decrease in clinical and ongoing pregnancy as well as implantation rates occurred from the lowest to the highest UC frequency groups (53%, 36%, 21%; 46%, 32%, 20%; 23%, 19%, 10%; and 14%, 11%, 4%; P < 0.001). Direction of UC did not affect ET outcome.
  
  
  CONCLUSIONS
  The negative correlation between UC frequency and P levels supports the utero-relaxing properties of P. High frequency UC on the day of ET hinder IVF-ET outcome, possibly by expelling embryos out of the uterine cavity.
authors.affiliation: Service de Gynécologie-Obstétrique, Hôpital Antoine Béclère, Clamart.
authors.forename: R
authors.initials: R
authors.lastname: Fanchin
authors.forename: C
authors.initials: C
authors.lastname: Righini
authors.forename: J M
authors.initials: JM
authors.lastname: Ayoubi
authors.forename: F
authors.initials: F
authors.lastname: Olivennes
authors.forename: D
authors.initials: D
authors.lastname: de Ziegler
authors.forename: R
authors.initials: R
authors.lastname: Frydman
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D010064:Embryo Implantation; D004624:Embryo Transfer; D004958:Estradiol / Q000097:blood; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D010062:Ovulation Induction; D011374:Progesterone / Q000097:blood; D011446:Prospective Studies; D014590:Uterine Contraction
chemical_list: D015415:Biomarkers; D011374:Progesterone; D004958:Estradiol