Uterine and Corpus Luteum Blood Flow Evaluation Prior to Uterine Flushing in Llama Embryo Donors

Abstract

The aim of this study was to assess the uterine blood flow (UBF) and corpus luteum blood flow (CLBF) in llamas 8 days post-mating, using color-Doppler ultrasonography (CDU), to determine the possible relationship between vascularization and the presence of an embryo. Adult females ( n = 25) were used to monitor ovarian dynamics by palpation and transrectal ultrasonography until detection of a ≥6 mm growing follicle. Females were randomly assigned to one of two groups: Group I ( n = 19), were mated and ovulation was induced by a single dose of buserelin (GnRH analog) that same day (Day 0); and Group II ( n = 6), only ovulation was induced (control). On Day 8, UBF and CLBF were evaluated transrectally in both groups. The color-flow images obtained were analyzed with Image J1.52a software to determine the vascularization area and the percentage of corpus luteum with blood flow emission (CLBF%) together with the percentage for each uterine horn (UBF%). Statistical analysis was performed using an ANOVA test. In Group I, uterine flushing was performed to obtain the embryos, thus dividing the females into Group I+ ( n = 10), when an embryo was recovered and Group I- ( n = 9), when no embryo was recovered. Embryo recovery rate was 52.63% (10/19). In Group I+, UBF% was significantly higher compared to Group I- and Group II ( P <0.05). UBF appears to be a good predictor for embryo presence, with an area under the curve (AUC) of 0.9 and an optimal cut-off value of 9.37% (with a sensitivity of 90% and specificity of 88.9%). The CLBF% did not differ between groups ( P > 0.05). In conclusion, it is possible to detect a local increase of UBF in the presence of an embryo on day 8 post-mating in llamas. This could be useful to achieve an early pregnancy diagnosis or to decide whether to carry out the uterine flushing in a llama embryo transfer program.

Acupuncture management in the field of assisted reproductive technology

“…The latest Doppler indices differed significantly between women with and without ovarian dysfunction and correlated significantly with markers of ovarian dysfunction, and these results support the use of Doppler ultrasound to detect ovarian dysfunction [17]. Patients undergoing IVF have a Doppler ultrasound of the uterine arteries before the day of egg retrieval, a test that is thought to be associated with success after embryo transfer [18]. Positive effects of acupuncture for infertility may be related to endorphin system inhibition of central sympathetic nerves, altered uterine blood flow and motility, and stress reduction [19].…”

Histomorphometric comparison of left and right oviduct structure from alpaca (Vicugna pacos)

“…This fact has lead researchers to generate several hypotheses about the existence of structural and functional differences in the reproductive tract on the left uterine horn that can affect female fertility (Del Campo et al, 1996; Sumar & Adams, 2006; Vaughan & Tibary, 2006). The relationship of vascularization in the uterus of llamas and the presence of an embryo was studied through Colour Doppler ultrasonography (CDU; Zampini et al, 2020); it showed a tendency of a higher blood flow in the presence of a corpus luteum in the left uterine horn compared to the right uterine horn. However, they did not find significant differences in blood flow between both uterine horns irrespective of the location of the corpus luteum in pregnant females.…”

“…This fact leads to hypothesize that developing embryos on the right side must migrate to the left side to maintain gestation (Sumar & Adams, 2006) or to prevent the systemic luteolytic effect of the left uterine horn (Vaughan & Tibary, 2006). An increase in estradiol‐17β has been demonstrated during early pregnancy (Powell et al, 2007), and its relationship with increased uterine blood flow (Zampini et al, 2020), which is explained by the interaction of the embryo with the uterine lumen (Picha et al, 2013; Tibary et al, 2013). Therefore, we can hypothesize the existence of structural differences between the left and right and the oviduct that may affect female fertility.…”

Effect of hCG administration on Day 7 post-mating on accessory corpus luteum development and progesterone concentration in llamas

“…All females were examined by transrectal doppler ultrasonography, every other day from Day 6 until Day 18 post-mating; in order to assess the ovulation of the largest follicle after treatment, the development of an accessory CL and the diameter and vascularization of both CLs (the original CL and the accessory CL). The vascularization of both CLs was evaluated as previously described [5,24,25]. Briefly, the transducer was placed over the ovary and three seconds video-clips of the CL vascularization were registered and downloaded.…”