The use of transvaginal power Doppler ultrasonography to evaluate the relationship between perifollicular vascularity and outcome in in-vitro fertilization treatment cycles.

Abstract

The aim of this prospective study of the use of transvaginal power Doppler ultrasound was to assess the subjectivity of the grading system and to elucidate, on a much larger series (200) of treatment cycles, the findings of previous authors. Vascular perfusion was studied using a grading system based on the percentage of follicular circumference (grade 1 < 25%, grade 2 < 50%, grade 3 < 75% and grade 4 > 75%) that depicted an echo signal. Interobserver variation was low (k = 0.81 + 0.08). A total of 1285 follicles were studied, of which 64% were of high (grades 3 or 4) and 36% were of low (grades 1 or 2) grade vascularity. Mean follicular diameter, oocyte retrieval rate, number of mature oocytes recovered and fertilization rates were all significantly higher (P < 0.05) and triploidy rate significantly lower (P < 0.05) from the cohort of follicles with high grade vascularity. There was no correlation between embryo morphology and vascularity grade. The pregnancy rate for cycles where the embryos transferred were derived from follicles with uniformly high grade (3 or 4 only) vascularity was significantly higher than for those cycles where the embryos transferred were derived from mixed (1 to 4) or low (1 or 2 only) grade follicles [24/72 (34.7%) versus 22/122 (18%); P < 0.05]. There were no significant differences in uterine artery or intraovarian pulsatility index values between the pregnant and non-pregnant treatment cycles. This study suggests that follicles with high grade vascularity are associated with better outcome variables. Thus, follicular assessment may be used prospectively to improve the outcome in in-vitro fertilization treatment cycles.