Colour Doppler changes and thromboxane production after ovarian stimulation with gonadotrophin-releasing hormone agonist

The objective of this study was to evaluate the Doppler flow variationswhich occur following the use of different protocols of ovarian stimulationin an IVF programme, and to investigate the thromboxane production bycultured endometrial cells and its influence on embryo implantation. Atotal of 60 patients underwent three different ovarian stimulationprotocols: long gonadotrophin-releasing hormone agonist (GnRH-a), shortGnRH-a and no GnRH-a. Transvaginal ultrasonography and colour Doppleranalysis were performed before and during the treatment. On the day thatthe Doppler examination took place, luteinizing hormone, folliclestimulating hormone, plasma oestradiol and thromboxane concentrations wereassayed. On the day of oocyte retrieval, endometrial cells were collectedand cultured, and their thromboxane production evaluated. No significantdifferences in hormonal, ultrasonographic or Doppler parameters wereobserved between the three groups. Ten out of 56 patients who had asuccessful embryo transfer became pregnant. In the group of pregnant womenthe pulsatility index values of both uterine and spiral arteries was lowerthan in non-pregnant patients, and was associated with significantly lowerthromboxane concentrations from cultured endometrial cells. It is concludedthat thromboxane plays a role in embryo implantation, and that Doppler flowanalysis of uterine and spiral arteries in infertile patients may beimportant in the management of ovarian stimulation.