Follicular vascularity--the predictive value of transvaginal power Doppler ultrasonography in an in-vitro fertilization programme: a preliminary study

The aim of this prospective study was to investigate the ability oftransvaginal power Doppler ultrasonography to assess the relationshipbetween follicular vascularity and outcome in women undergoing in-vitrofertilization. Each of 38 subjects underwent a single transvaginal powerDoppler ultrasound scan on the day of oocyte collection, where thevascularity of individual ovarian follicles was assessed, using asubjective system, and graded 1 to 4. In addition, conventional pulsatilityindices (PI) of the uterine and intra-ovarian (stromal) arteries werecalculated, which showed no significant differences between the pregnantand non-pregnant groups. Using power Doppler ultrasonography, a total of188 follicles was studied. The follicular vascularity grade was found to beindependent of follicular size and there was no significant difference infertilization rates with different degrees of vascularity, although therewas a trend towards higher fertilization rates with higher gradevascularity. There were 10 pregnancies, giving a pregnancy rate of 26.3%per embryo transfer. Pregnancies were confined to those women whose embryoswere derived from follicles with grade 3 and 4 vascularity (pregnancy ratesper embryo transfer of 12.5 and 61.5% respectively), with only those fromgrade 4 follicles resulting in livebirths. This preliminary study suggestedthat high grade follicular vascularity is associated with increasedpregnancy rate and that there is a possible link between follicularvascularity and implantation potential.