Progestin priming before gonadotrophin stimulation and AI improves embryo development and normalises luteal function in the cat

Prolonged glucocorticoid administration affects oocyte morphology in cats (Felis catus) undergoing an ovarian stimulation protocol

While captivity-related stress and the associated rise in baseline glucocorticoid (GC) concentrations have been linked to ovarian quiescence in some felid species, no study has examined the effects of elevated GC on oocyte quality. This study examined the effects of exogenous GC administration on the ovarian response and oocyte quality of domestic cats after an ovarian stimulation protocol. Entire mature female cats were divided into treatment (n = 6) and control (n = 6) groups. Cats in the GC treatment (GCT) group were given 1 mg kg-1 oral prednisolone daily from Day 0-45. All cats (n = 12) were given 0.088 mg kg-1 day-1 progesterone orally from Day 0-37, before treatment with 75 IU eCG im to induce follicular growth on Day 40, followed by 50 IU hCG im 80 h later to induce ovulation. Cats were ovariohysterectomised 30 h after the hCG treatment. Blood samples were collected on Days 0, 10, 30 and 40 (prior to eCG treatment), 80 h after eCG treatment, and on Day 45 for cortisol, glucose, prednisolone, oestradiol, and progesterone analysis. Cortisol concentrations did not differ between treatment groups throughout the study. Mean glucose concentrations were higher in the GCT cats (P = 0.004). Prednisolone was undetectable in all samples. Oestradiol and progesterone concentrations confirmed that the eCG treatment stimulated follicular activity and ovulation in all cats. Following ovariohysterectomy, the ovarian responses were graded (1 = excellent, 4 = poor) and oocytes retrieved from the oviducts. Each oocyte was given a total oocyte score (TOS: using an 9-point scale, 8 = best) based on four parameters: oocyte morphology, size, ooplasm uniformity and granularity, and zona pellucida (ZP) thickness and variation. Ovulation was confirmed in all cats, with a mean of 10.5 ± 1.1 ovulations per cat. Ovarian mass, ovarian response, number of ovulations, and oocyte recovery did not differ between groups. Oocyte diameter did not differ between the groups, but the ZP was thinner in the GCT group (3.1 ± 0.3 μm vs. 4.1 ± 0.3 μm, P = 0.03). The TOS was similar between treatment and control cats, but the ooplasm grade was lower (1.5 ± 0.1 vs. 1.9 ± 0.1, P = 0.01) and there was a tendency for ZP grade to be poorer (0.8 ± 0.1 vs. 1.2 ± 0.2; P = 0.08) in the treatment group. In conclusion, the GC treatment resulted in morphological changes to oocytes collected following ovarian stimulation. Whether these changes would affect fertility warrants further investigation.

Ovulation induction with high progesterone levels may be more suitable for elderly patients with low ovarian response

BACKGROUND

The objective of this study was to explore the outcomes of using the progestin-primed ovarian stimulation (PPOS) protocol in aged infertile women. The patients recruited in the study had displayed a poor ovarian response (POR) in the first IVF/ICSI-ET cycles with the ultra-short gonadotropin-releasing hormone agonist (GnRH-a) protocols.

MATERIALS AND METHODS

A self-controlled retrospective study was conducted to investigate the clinical outcomes of 117 aged infertile women who met the inclusion criteria. The patients were grouped into two; group B included patients who had displayed a poor ovarian response (POR) in the first IVF/ICSI-ET cycle with the ultra-short GnRH-a protocol. Group A was made up of patients who underwent the PPOS protocol in the second cycle. The study was done between January 2015 to May 2018 in the reproductive and genetic centre of integrated traditional and western medicine, Affiliated hospital of Shandong University of traditional Chinese medicine. Reproduction-related clinical outcomes in the two groups were compared.

RESULTS

There were no statistically significant differences in the serum levels of LH, E_2, and P on the trigger day between group A and group B (P＞0.05). The number of follicles with a diameter > 14 mm was significantly higher in the PPOS protocol patients than in the ultra-short GnRH-a protocol group (4.83 ± 2.82 vs. 3.25 ± 2.53, P < 0.01). The duration and total dosage of gonadotropin of the PPOS protocol group were less than in the previous ultra-short GnRH-a protocol, although the statistical differences were not significant (P > 0.05). The number of eggs obtained in the PPOS group was significantly higher than that of the previous one (4.29 ± 3.11 vs. 2.76 ± 2.33, P < 0.05). The numbers of MII eggs, cleavage, 2 P N, transplantable embryos, and high quality embryos were higher in the PPOS protocol group than that in the ultra-short protocol group. However, the differences between the two groups in all the above parameters were not statistically significant (P > 0.05). The rate of high-quality embryos was significantly higher in the PPOS protocol group than in the ultra-short protocol group (38.61(100/259) vs. 32.02(65/203), P < 0.05). Although not statistically significant (P > 0.05), the abortion rate of the PPOS protocol group was higher than that of the ultra-short protocol group. The clinical pregnancy and live birth rates were significantly higher in the PPOS protocol group than in the ultra-short protocol group (p < 0.05). The clinical pregnancy rates in the PPOS protocol group and the ultra-short protocol group were 32.35 % and 25.53 % respectively while the live birth rates were 27.45 % and 21.28 % respectively.

CONCLUSION

Compared with the ultra-short protocol, the PPOS protocol improves the number of follicles, the number of eggs, clinical pregnancy, and live birth rates in POR patients. The PPOS protocol could, therefore, provide a novel treatment strategy for inducing ovulation in POR patients.

Responsiveness of the cheetah (Acinonyx jubatus) ovary to exogenous gonadotropins after preemptive oral progestin treatment

Control of ovarian function in cheetahs is sub-optimal, which currently limits the integration of assisted reproductive techniques into the genetic management of that endangered species. The objective of this study was to determine the effect of preemptive progestin treatment on the quality of ovarian responses after exogenous gonadotropin stimulation in cheetahs. Adult females received either 1) 200 IU equine chorionic gonadotropin (eCG) followed with 3,000 IU porcine luteinizing hormone (pLH) (intramuscular route) (n = 5; control group) or 2) similar eCG/pLH administration preceded by a 7-day treatment with oral progestin (0.1 mg/kg altrenogest; ALT group; n = 7). At 42 h post-pLH administration, a series of metrics was assessed via laparoscopy (number of follicles ≥ 2 mm, number of corpora lutea, oviduct and uterine cornua diameter and overall vascularization). Concentrations of fecal estradiol, progesterone and glucocorticoid metabolites (FEM, FPM, and FGM, respectively) were measured by enzyme immunoassay for 3 wk before ALT treatment (Period 1), 7 d during ovarian suppression period (Period 2), throughout eCG/LH treatment and laparoscopy (Period 3), and 6 wk following laparoscopy (Period 4). Overall, nine out of 12 cheetahs (4/5 in control and 5/7 ALT group) had freshly-formed corpora lutea at the time of laparoscopy. Mean follicle and corpora lutea numbers in the control versus ALT group were not different (P > 0.05). Overall measurements and vascularization scores also did not differ (P > 0.05) among groups. FEM average concentrations increased (P ≤ 0.05) in response to eCG for the ALT-treated females between Periods 2 and 3 and were sustained during Period 4. However, FEM average concentrations did not vary (P > 0.05) for control females throughout Periods 1-4. Post-ovulatory FPM average concentrations (Period 4) did not differ (P > 0.05) between the ALT-treated females and controls. FPM average concentration from both groups increased in Period 4 compared to Periods 1-3 (P ≤ 0.05). Females receiving the ALT treatment also had lower (P ≤ 0.05) FGM metabolite average concentrations than control females during ovarian suppression (suggesting adrenal suppression). Collective results suggest that ovarian response to gonadotropin treatment in the cheetah was improved following oral progestin administration due to the normative increase in estradiol following stimulation for these females compared with control. This treatment should lead to more effective timed assisted reproduction procedures for this species.

Practical application of laparoscopic oviductal artificial insemination for the propagation of domestic cats and wild felids

AI was first reported in cats almost 50 years ago but, unlike AI in other domesticated animals (e.g. dogs, cattle, horses), has not been widely used for routine propagation by veterinarians or breeders. Anatomical and physiological challenges with cats have hindered the efficiency of AI using standardised transcervical approaches applied to other species. Development of laparoscopic oviductal AI (LO-AI) has helped overcome some of these barriers and, during the past 7 years, produced high pregnancy percentages (>70%) in domestic cats using both fresh collected and frozen-thawed semen and resulted in the birth of full-term offspring in three cat hereditary disease models and six wild cat species (ocelot, Pallas's cat, fishing cat, sand cat, tiger, clouded leopard). The standard approach involves exogenous gonadotrophin treatment (typically equine chorionic gonadotrophin followed by porcine LH) to induce ovarian follicular growth and ovulation, with laparoscopic visualisation of the oviductal ostium for direct intraluminal insemination with low numbers of spermatozoa. Similar ovarian synchronisation and insemination approaches have been used with wild felids, but frequently must be refined on a species-by-species basis. From a practical perspective, LO-AI in domestic cats now has adequate efficiency for applied use as a reproductive service in veterinary practices that possess basic laparoscopy expertise.

Circumventing the natural, frequent oestrogen waves of the female cheetah (Acinonyx jubatus) using oral progestin (Altrenogest)

Cheetah are induced ovulators, experiencing short, variable oestrogen waves year-round. Exogenous gonadotrophin administration induces ovulation, but success is variable and often improves if ovaries are quiescent. After affirming the presence of short-term oestrogenic waves, we examined the effect of the timing of administration of exogenous equine and human chorionic gonadotrophins (eCG-hCG) within the oestrogen concentration pattern on subsequent follicle development and oocyte and corpus luteum quality. We also investigated ovarian suppression using an oral progestin (Altrenogest, 7 days) and assessed whether Altrenogest moderated adrenal activity by reducing glucocorticoid metabolites. All cheetahs exhibited short (every ~7-10 days), sporadic, year-round increases in faecal oestradiol punctuated by unpredictable periods (4-10 weeks) of baseline oestradiol (anoestrous). Gonadotrophin (eCG-hCG) efficacy was not affected by oestradiol 'wave' pattern if administered ≥3 days after an oestrogen peak. Such cheetahs produced normative faecal progestagen patterns and higher numbers (P<0.06) of mature oocytes than females given gonadotrophins ≤2 days after an oestradiol peak. Altrenogest supplementation expanded the interval between oestradiol peaks to 12.9 days compared with 7.3 days without progestin pretreatment. Altrenogest-fed females excreted less (P<0.05) glucocorticoid metabolites than non-supplemented counterparts. Results show that Altrenogest is effective for suppressing follicular activity, may contribute to reduced glucocorticoid production and may result in more effective ovulation induction via gonadotrophin therapy.