title: Cycle-to-cycle variation in utero-ovarian hemodynamic indices in ovarian stimulation and natural cycles of the same women and its effect on the outcome of assisted reproduction treatment.
abstract: OBJECTIVE
  To investigate the blood flow parameters between cycles of the same women to assess whether parameters predicting a successful pregnancy in a stimulation cycle could be used to determine the outcome of subsequent natural cycles.
  
  
  METHODS
  A prospective study.
  
  
  METHODS
  Assisted reproduction unit, the University of Hong Kong.
  
  
  METHODS
  Fifty-eight IVF cycles and 40 natural cycles were evaluated.
  
  
  METHODS
  Assessments of the utero-ovarian pulsatility indices (PIs), resistance indices (RIs), and endometrial color signals.
  
  
  RESULTS
  In IVF cycles, the pregnancy rate (27%) was similar to that in frozen-thawed embryo transfer (FET) (28%) cycles. The utero-ovarian PIs and RIs in IVF cycles were significantly lower than those in the natural cycles. There was a significant correlation between the uterine PI in stimulation cycles and that in natural cycles. In IVF cycles, the pregnancy rate declined significantly when the uterine PI was >2.70 and the RI was >0.9. In FET cycles, no decline in pregnancy rate was seen. Conceptional FET cycles showed significantly higher uterine PI, uterine RI, and endometrial color signals compared with conceptional IVF cycles.
  
  
  CONCLUSIONS
  Hemodynamic parameters in stimulation cycles are different from those in natural cycles, and the values of various parameters in predicting pregnancy are also different.
authors.affiliation: Department of Obstetrics and Gynecology, Queen Mary Hospital, University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: Ghazala Sikandar
authors.initials: GS
authors.lastname: Basir
authors.forename: Tina Poy Wing
authors.initials: TP
authors.lastname: Lam
authors.forename: Wai sum
authors.initials: Ws
authors.lastname: O
authors.forename: Ming Tak
authors.initials: MT
authors.lastname: Chau
authors.forename: Ernest Hung Yu
authors.initials: EH
authors.lastname: Ng
authors.forename: Pak Chung
authors.initials: PC
authors.lastname: Ho
mesh_terms: D015925:Cryopreservation; D004622:Embryo, Mammalian; D004717:Endometrium / Q000000981:diagnostic imaging; D005260:Female; D005307:Fertilization in Vitro; D005544:Forecasting; D006439:Hemodynamics; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D010053:Ovary / Q000098:blood supply*; D010062:Ovulation Induction; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D011674:Pulse; D012016:Reference Values; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color; D014599:Uterus / Q000098:blood supply*; D014655:Vascular Resistance