The aim of this prospective study was to investigate the ability of transvaginal power Doppler ultrasonography to assess the relationship between follicular vascularity and outcome in women undergoing in-vitro fertilization. Each of 38 subjects underwent a single transvaginal power Doppler ultrasound scan on the day of oocyte collection, where the vascularity of individual ovarian follicles was assessed, using a subjective system, and graded 1 to 4. In addition, conventional pulsatility indices (PI) of the uterine and intra-ovarian (stromal) arteries were calculated, which showed no significant differences between the pregnant and non-pregnant groups. Using power Doppler ultrasonography, a total of 188 follicles was studied. The follicular vascularity grade was found to be independent of follicular size and there was no significant difference in fertilization rates with different degrees of vascularity, although there was a trend towards higher fertilization rates with higher grade vascularity. There were 10 pregnancies, giving a pregnancy rate of 26.3% per embryo transfer. Pregnancies were confined to those women whose embryos were derived from follicles with grade 3 and 4 vascularity (pregnancy rates per embryo transfer of 12.5 and 61.5% respectively), with only those from grade 4 follicles resulting in livebirths. This preliminary study suggested that high grade follicular vascularity is associated with increased pregnancy rate and that there is a possible link between follicular vascularity and implantation potential.
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.
These data would suggest that perifollicular vascularity has an important role to play in the outcome of IUI cycles, and that power Doppler has the potential to refine the management of assisted reproduction treatment cycles.
Concentrations of both cortisol and cortisone were significantly lower in FF samples obtained from patients that conceived by IVF-ET than in those obtained from nonconception cycles. Conception by gonadotrophin-stimulated IVF-ET was associated with an elevated intrafollicular ratio of cortisol:cortisone, consistent with a low level of intraovarian cortisol oxidation by 11betaHSD.
A common response of animals to physical restraint is tonic immobility. The authors observed the behavior of garter snakes, Thamnophis elegans, in the field to determine the frequency of immobility as a response to handling. Most snakes fled after release, but the remainder remained immobile, sometimes on their backs (supination), for up to 10 min. Immobility was seen most often in pregnant snakes, which also were more likely than other snakes not to have moved before capture. Failure to move, either before or after capture, might be a consequence of the limited locomotory ability of gravid snakes. However, the lack of observations of interactions between snakes and their natural predators impedes researchers' understanding of the antipredator value, if any, of tonic immobility.
In-vitro fertilization provides evidence for the heterogeneity of human embryos; data from the UK indicating that approximately 90% of embryos selected for transfer fail to implant. The need to identify factors that promote implantation or markers of implantation is self-evident. There is an increasing awareness that the heterogeneity of follicles may have a significant impact on oocyte competence and embryo viability and that factors which contribute to the heterogeneity of follicles may provide markers of implantation in assisted conception. The markers of implantation described include the expression of 11 beta-hydroxysteroid dehydrogenase by granulosa cells in vitro; adhesion and proliferation of cumulus cells in vitro; steroidogenic activity of cumulus in vitro and perifollicular vascularity and vascular endothelial growth factors bound to granulosa and cumulus cells. These factors may provide clinically useful markers of implantation potential.
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