Prediction of Ovarian Hyperstimulation Syndrome in Patients Treated with Corifollitropin alfa or rFSH in a GnRH Antagonist Protocol

Study Question

What is the threshold for the prediction of moderate to severe or severe ovarian hyperstimulation syndrome (OHSS) based on the number of growing follicles ≥ 11 mm and/or estradiol (E₂) levels?

Summary Answer

The optimal threshold of follicles ≥11 mm on the day of hCG to identify those at risk was 19 for both moderate to severe OHSS and for severe OHSS. Estradiol (E₂) levels were less prognostic of OHSS than the number of follicles ≥ 11 mm.

What Is Known Already

In comparison to long gonadotropin-releasing hormone (GnRH) agonist protocols, the risk of severe OHSS is reduced by approximately 50% in a GnRH antagonist protocol for ovarian stimulation prior to in vitro fertilisation (IVF), while the two protocols provide equal chances of pregnancy per initiated cycle. Nevertheless, moderate to severe OHSS may still occur in GnRH antagonist protocols if human chorionic gonadotropin (hCG) is administered to trigger final oocyte maturation, especially in high responder patients. Severe OHSS following hCG trigger may occur with an incidence of 1–2% in a relatively young (aged 18 to 36 years) IVF population treated in a GnRH-antagonist protocol.

Study Design, Size, Duration

From the Engage, Ensure and Trust trials, in total, 2,433 women who received hCG for oocyte maturation and for whom the number of follicles ≥ 11 mm and the level of E₂ on the day of hCG administration were known were included in the analyses.

Participants/Materials, Setting, Methods

The threshold for OHSS prediction of moderate and severe OHSS was assessed in women treated with corifollitropin alfa or daily recombinant follicle stimulation hormone (rFSH) in a gonadotropin-releasing hormone (GnRH)-antagonist protocol. Receiver operating characteristics curve analyses for moderate to severe OHSS and severe OHSS were performed on the combined dataset and the sensitivity and specificity for the optimal threshold of number of follicles ≥ 11 mm, E₂ levels on the day of (hCG), and a combination of both, were determined.

Main Results and the Role of Chance

The optimal threshold of follicles ≥ 11 mm on the day of hCG to identify those at risk of moderate to severe OHSS was 19 (sensitivity and specificity 62.3% and 75.6%, respectively) and for severe OHSS was also 19 (sensitivity and specificity 74.3% and 75.3%, respectively). The positive and negative predictive values were 6.9% and 98.6%, respectively, for moderate to severe OHSS, and 4.2% and 99.5% for severe OHSS.

Limitations, Reasons for Caution

This was a retrospective analysis of combined data from three trials following ovarian stimulation with two different gonadotropins.

Wider Implications of the Findings

For patients with 19 follicles or more ≥11 mm on the day of hCG, measures to prevent the development of OHSS should be considered. Secondary preventive measures include cycle cancellation or coasting, use of a GnRH agonist to trigger final oocyte maturation in place of hCG and a freeze all strategy.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00702845","term_id":"NCT00702845"}}NCT00702845{"type":"clinical-trial","attrs":{"text":"NCT00696800","term_id":"NCT00696800"}}NCT00696800{"type":"clinical-trial","attrs":{"text":"NCT00696878","term_id":"NCT00696878"}}NCT00696878     

Elective frozen-thawed embryo transfer (FET) in women at risk for ovarian hyperstimulation syndrome

Elective cryopreservation of cultured embryos has become a treatment option for women at risk for ovarian hyperstimulation syndrome (OHSS). The aim of our study was to investigate the outcome of elective cryopreservation and consecutive frozen-thawed embryo transfer (FET) in a large IVF clinic in Austria. A total of 6104 controlled ovarian hyperstimulation cycles (COH) were performed on 2998 patients including 200 patients (6.7%) who were undergoing elective cryopreservation and FET due to high risk of OHSS. We estimated the cumulative live birth rate using the Kaplan-Meier method and evaluated independent predictors for successful live births with a Cox model. A total of 270 frozen-thawed embryo transfers were performed on 200 patients with up to 4 transfers per patient. The first embryo transfer showed a live birth rate of 42.0%, the second transfer showed a cumulative rate of 58.5%. After a total of 4 FETs from the same COH cycle, a cumulative live birth rate of 61.0% per COH cycle could be achieved. Four cases of OHSS occurred amongst these patients (2.0%), all of them of moderate severity. Multivariate analysis identified maternal age, the use of assisted hatching and the number of embryos transferred at the blastocyst stage as independent predictors for cumulative live birth. Our study clearly suggests that elective FET is safe and shows excellent cumulative live birth rates. This concept can, therefore, be used to avoid the severe adverse events caused by COH and the inefficient use of cultured embryos.     

Diagnosing and management of iatrogenic moderate and severe ovarian hyperstymulation syndrome (OHSS) in clinical material

Severe ovarian hyperstymulation syndrome is a rare but potentially life-threatening complication in patients undergoing assisted reproductive techniques (ART). The pathogenesis of this condition is likely to be multifactorial. The aim of the retrospective study was to present management in moderate and severe iatrogenic ovarian hyperstymulation syndrome (OHSS) in clinical material. The study group was 19 women, admitted to the Department of Obstetrics and Gynecology in Central Clinical Hospital of Ministry of Interior and Administration in Warsaw from large outpatient infertility center "Novum" in Warsaw with moderate and severe OHSS between 14.07.2004 and 8.11.2005. Laboratory tests and ultrasound examination of the ovarian size and ascites were performed, abdominal circumference was measured. Patients were treated with rehydration with intravenous crystalloids and colloids, diuretics, antibiotics, anticoagulants and ultrasound-guided paracentesis if symptoms of ascites become severe (ascites causes pain and compromised pulmonary function). Oral intake of water was restricted, monitoring of fluid intake and output, and daily monitoring of body weight was performed. During treatment controlled laboratory tests were done. In one patient occurred intra-abdominal hemorrhage from ovarian rupture and laparotomy with oophorectomy was performed. The ovarian hyperstimulation syndrome is still a difficult diagnostic and therapeutic problem and more studies are required to elucidate pathophysiology of OHSS. Because of still unknown etiology treatment is empirical and in most of cases bases on experience of medical team. Thus, the management in individual patients varies according to the severity of ovarian hyperstymulation syndrome and its complications.     

Impact of GnRH analogues on oocyte/embryo quality and embryo development in in vitro fertilization/intracytoplasmic sperm injection cycles: a case control study

Background  

Despite the clinical outcomes of ovarian stimulation with either GnRH-agonist or GnRH-antagonist analogues for in vitro fertilization (IVF) being well analysed, the effect of analogues on oocyte/embryo quality and embryo development is still not known in detail. The aim of this case-control study was to compare the efficacy of a multiple-dose GnRH antagonist protocol with that of the GnRH agonist long protocol with a view to oocyte and embryo quality, embryo development and IVF treatment outcome.     

Superovulatory responses to eCG in llamas (Lama glama )

Llamas are copulation-induced single-ovulators, and multiple ovulation and embryo transfer (MOET) methods have not yet been developed for this species. Superovulatory responses to eCG given during an induced (Group A) or simulated (Group B) luteal phase were investigated using ultrasound to observe ovarian follicles and corpora lutea (CLs) and plasma progesterone was used to assess luteal function. Embryos were recovered nonsurgically. Group A (n = 19): donors were given 8 microg, im GnRH analogue (Day 0) to induce ovulation of a mature follicle, 1000 IU, im eCG (Day 7), and 250 microg PGF(2alpha) analogue (Day 9). Group B (n = 17): donors were given a subcutaneous progestagen implant (3 mg Norgestomet) at Days 0 to 7) and 1000 IU, im eCG (Day 5). When most (>65%) of the follicles in both Groups A and B had matured at 5 to 11 d post eCG, the donors were given 8 microg, im GnRH and mated once (n = 26) or twice within a 24-h interval (n = 10); embryos were recovered 6 to 9 d post ovulation. More follicles and corpora lutea were induced in Group B than in Group A, but a similar mean number of embryos were recovered (1.3 vs 1.6), and a similar proportion of donors yielded multiple embryos (35 vs 32%). The embryo recovery rate was similar for Groups A and B (39 and 37%), but it was higher (P < 0.001) with 2 (72%) rather than 1 (22%) mating, and it was negatively correlated with CL number (P < 0.05). Overall, 80% of the llamas had a precocious CL and elevated plasma progesterone concentrations when multiple follicles reached maturity. This was associated with increased subsequent superovulation and embryo recovery (P < 0.01). Peak plasma progesterone was positively correlated with the CL number (P < 0.05). From these results we conclude that superovulation may be achieved with eCG given during either an induced or a simulated luteal phase, that embryo recovery is improved following 2 matings rather than 1, and that MOET may indeed be feasible for use in the llama.     

The association between treatment parameters on the day of gonadotropin-releasing hormone antagonist initiation during a flexible protocol and oocyte maturation rate

This study aimed to evaluate the effects of different treatment parameters on the day of GnRH antagonist initiation on oocyte maturation rate. We performed a retrospective cohort study of women aged ≤ 38 who underwent their first IVF-ICSI treatment using a flexible GnRH antagonist protocol in a single university-affiliated medical center during 2005-2015. Treatment parameters of three groups of oocyte maturation rates (<60%, 60-90%,>90%) were compared. Multivariate analysis was conducted to detect an association between treatment parameters on the day of GnRH antagonist initiation and oocyte maturation rate. The cohort included 458 patients, of whom 180 (39%) had a high oocyte maturation rate (≥90%), 211 (46%) had an oocyte maturation rate between 60-90% and 67 (15%) had a low maturation rate (≤60%). Women with a high maturation rate had longer duration of treatment (10.3 ± 2.9 days vs. 9.6 ± 2.5 vs. 9.5 ± 3.2, P = 0.019), lower levels of estradiol (1985 ± 1357 vs. 2406 ± 1666 vs. 2325 ± 1811, P = 0.027) and lower estradiol/maximal follicular diameter ratio on the day of GnRH antagonist initiation (137 ± 89 vs. 165 ± 103 vs. 163 ± 125, P = 0.019) as compared to women with medium and low maturation rates, respectively. Using linear regression multivariate analysis, lower estradiol and lower estradiol/maximal follicular diameter ratio on GnRH antagonist initiation day were associated with higher oocyte maturation rate. Further prospective studies to determine the best timing for GnRH antagonist initiation are needed.     

Assisted reproductive technologies: how to minimize the risks and complications in developing countries?

¹ Correspondence address. E-mail: petra.desutter{at}ugent.be In 2% of assisted reproductive techniques (ART) cycles complicationsoccur. Some are preventable, some are not. In this paper, wewill discuss risks and complications of the standard ‘Western’approach in ART today and point to some measures to be takenwhen implementing ART in developing countries, where resourcesand access to medical care may be limited. Ovarian hyperstimulationsyndrome (OHSS, and its thrombo-embolic complications) is responsiblefor the majority of cycle-related complications, followed bybleeding and infection at oocyte retrieval. ART pregnanciesare complicated by first-trimester bleeding more often thanspontaneous pregnancies, they are more often ectopic, but themajor complication is the very high incidence of multiple pregnancies,when more than one embryo is transferred. OHSS can be preventedby screening patients at risk and by using mild or no stimulation.Simple measures can minimize the risks of bleeding or infection.Obviously single embryo transfer is the only way to avoid multiplepregnancies, which have a highly increased risk for severe maternaland neonatal morbidity and mortality (mainly due to prematurity).Special attention should be given to pre-existing pathologies.Risk minimization of ART in developing countries is not onlymandatory from an economical but also an ethical point of view.     

Comparisons of GnRH Antagonist versus GnRH Agonist Protocol in Supposed Normal Ovarian Responders Undergoing IVF: A Systematic Review and Meta-Analysis

Objective

To evaluate the effectiveness and safety of GnRH antagonist and GnRH agonist in supposed normal ovarian responders undergoing IVF.

Methods

Data from 6 databases were retrieved for this study. The RCTs of GnRH agonist and GnRH antagonist use during IVF-EF therapy for patients with supposed normal ovarian response were included. A meta-analysis was performed with Revman 5.1software.

Results

Twenty-three RCTs met the inclusion criteria. The number of stimulation days (mean difference (MD): −0.66, 95% confidence interval (CI): −1.04∼−0.27), Gn amount (MD: −2.92, 95% CI: −5.0∼−0.85), E2 values on the day of HCG (MD: −330.39, 95% CI: −510.51∼−150.26), Number of oocytes retrieved (MD: −1.33, 95% CI: −2.02∼−0.64), clinical pregnancy rate (odds ratio (OR): 0.87, 95% CI: 0.75−1.0), and ovarian hyperstimulation syndrome (OHSS) incidence (OR: 0.59, 95% CI: 0.42∼0.82) were significantly lower in GnRH antagonist protocol than GnRH agonist protocol. However, the endometrial thickness on the day of HCG (MD: −0.04, 95% CI: −0.23∼0.14), the ongoing pregnancy rate (OR: 0.87, 95% CI: 0.74∼1.03), live birth rate (OR: 0.89, 95% CI: 0.64∼1.24), miscarriage rate (OR: 1.17, 95% CI: 0.85∼1.61), and cycle cancellation rate (OR: 1.11, 95% CI: 0.90∼1.37) did not significantly differ between the 2 groups.

Conclusions

During IVF treatment for patients with supposed normal responses, the incidence of OHSS were significantly lower, whereas the ongoing pregnancy and live birth rates were similar in the GnRH antagonist compared with the standard long GnRH agonist protocols.     

Effect of luteal-phase support on endometrial microRNA expression following controlled ovarian stimulation

ABSTRACT: BACKGROUND: Studies suggested that microRNAs influence cellular activities in the uterus including cell differentiation and embryo implantation. In assisted reproduction cycles, luteal phase support, given to improve endometrial characteristics and to facilitate the implantation process, has been a standard practice. The effect of different types of luteal phase support using steroid hormones in relation to endometrial miRNA profiles during the peri-implantation period has not seen described. This study was designed to evaluate the expression of miRNAs during the luteal phase following controlled ovarian stimulation for IVF and the influence of different luteal phase support protocols on miRNA profiles. METHODS: The study was approved by the Johns Hopkins Hospital Institutional Review Board. Endometrial biopsies were obtained on the day of oocyte retrieval from 9 oocyte donors (group I). An additional endometrial biopsy was obtained 3-5 days later (Group II) after the donors were randomized into three groups. Group IIa had no luteal-phase support, group IIb had luteal support with micronized progesterone (P), and Group IIc had luteal support with progesterone plus 17-beta-estradiol (P+E). Total RNA was isolated and microarray analysis was performed using an Illumina miRNA expression panel. RESULTS: A total of 526 miRNAs were identified. Out of those, 216 miRNAs were differentially regulated (p<0.05) between the comparison groups. As compared to the day of retrieval, 19, 11 and 6 miRNAs were differentially regulated more than 2 fold in the groups of no support, in the P support only, and in the P+E support respectively, 3-5 days after retrieval. During the peri-implantation period (3-5 days after retrieval) the expression of 33 and 6 miRNAs increased, while the expression of 3 and 0 miRNAs decreased, in the P alone and in the P+E group respectively as compared to the no steroid supplementation group. CONCLUSION: Luteal support following COS has a profound influence on miRNA profiles. Up or down regulation of miRNAs after P or P+E support suggest a role(s) of luteal support in the peri-implantation uterus in IVF cycles through the regulation of associated target genes.     

In vitro oocyte maturation and preantral follicle culture from the luteal-phase baboon ovary produce mature oocytes

Female cancer patients who seek fertility preservation but cannot undergo ovarian stimulation and embryo preservation may consider 1) retrieval of immature oocytes followed by in vitro maturation (IVM) or 2) ovarian tissue cryopreservation followed by transplantation or in vitro follicle culture. Conventional IVM is carried out during the follicular phase of menstrual cycle. There is limited evidence demonstrating that immature oocyte retrieved during the luteal phase can mature in vitro and be fertilized to produce viable embryos. While in vitro follicle culture is successful in rodents, its application in nonhuman primates has made limited progress. The objective of this study was to investigate the competence of immature luteal-phase oocytes from baboon and to determine the effect of follicle-stimulating hormone (FSH) on baboon preantral follicle culture and oocyte maturation in vitro. Oocytes from small antral follicle cumulus-oocyte complexes (COCs) with multiple cumulus layers (42%) were more likely to resume meiosis and progress to metaphase II (MII) than oocytes with a single layer of cumulus cells or less (23% vs. 3%, respectively). Twenty-four percent of mature oocytes were successfully fertilized by intracytoplasmic sperm injection, and 25% of these developed to morula-stage embryos. Preantral follicles were encapsulated in fibrin-alginate-matrigel matrices and cultured to small antral stage in an FSH-independent manner. FSH negatively impacted follicle health by disrupting the integrity of oocyte and cumulus cells contact. Follicles grown in the absence of FSH produced MII oocytes with normal spindle structure. In conclusion, baboon luteal-phase COCs and oocytes from cultured preantral follicles can be matured in vitro. Oocyte meiotic competence correlated positively with the number of cumulus cell layers. This study clarifies the parameters of the follicle culture system in nonhuman primates and provides foundational data for future clinical development as a fertility preservation option for women with cancer.     

Anti-Mullerian hormone levels decline under hormonal suppression: a prospective analysis in fertile women after delivery

Aromatase inhibitors have been introduced as a new treatment modality that could challenge clomiphene citrate as an ovulation induction regiment in patients with PCOS. Although several randomized trials have been conducted regarding their use as ovulation induction agents, only few trials are available regarding their efficacy in IVF stimulated cycles. Current available evidence support that letrozole may have a promising role in stimulated IVF cycles, either when administered during the follicular phase for ovarian stimulation. Especially for women with poor ovarian response, letrozole appears to have the potential to increase clinical pregnancy rates when combined with gonadotropins, whereas at the same time reduces the total gonadotropin dose required for ovarian stimulation. However, given that in all of the trials letrozole has been administered in GnRH antagonist cycles, it is intriguing to test in the future how it may perform when used in GnRH agonist cycles. Finally administration of letrozole during luteal phase in IVF cycles offers another treatment modality for patients at high risk for OHSS taking into account that it drastically reduces estradiol levels     

Conséquences de la chimiothérapie anticancéreuse sur la fertilité de la femme

Sterility is a potential toxic effect of chemotherapy. This risk is well established for alkylating agents, but is less clearly defined for anthracyclines, methotrexate and fluorouracil and poorly defined for alkaloids, platinum, etoposide and taxanes. The main predictive factors for ovarian toxicity are the additive effect of cytotoxic drugs, the cumulative dose of each drug and the patient’s age. This effect of chemotherapy is evaluated on menstrual cycles, hormonal assays and the number of pregnancies observed in patient cohorts. Chemotherapy induces destruction of oocytes and granulosa cells. In mice, it has been shown that adriamycin may induce oocyte apoptosis, which can be prevented by modulation of cycle cell signalling (dysregulation of Bax gene or, on the contrary, expression of its antagonist gene Bcl-2 or inhibition of apoptosis with sphingosine-1-phosphate or caspase inhibitors). Clinical data in the literature are usually based on retrospective studies and are somewhat confused: global fertility after MOPP chemotherapy for Hodgkin’s disease is about 20%, adjuvant chemotherapy with CMF, F(A)C or TAC for breast cancer induces amenorrhea in 50% to 70% of cases, PVB or BEP chemotherapy for ovarian germ cell tumors has little effect on fertility when the uterus and one ovary can be preserved, and the majority of women treated with methotrexate, actinomycin D or various combinations for persistent trophoblastic disease remain fertile. Preservation of fertility is a major goal for cancer patients receiving chemotherapy: in vitro fertilization could preserve the couple’s fertility, but is usually not feasible as it would delay initiation of chemotherapy until after stimulation of ovulation; oocyte or ovarian tissue cryopreservation is at the stage of research; oral contraceptives have not been demonstrated to be effective to preserve ovarian function; gonadotropin releasing hormone (GnRH) agonists prevent cyclophosphamide toxicity in rat and monkey ovaries, and a few pilot clinical studies suggest that chemotherapy-induced amenorrhea could be prevented by administration of GnRH analogues simultaneously to chemotherapy, but randomised studies are necessary.     

A randomized controlled trial of the GnRH antagonist ganirelix in Chinese normal responders: high efficacy and pregnancy rates

Gonadotropin-releasing hormone (GnRH) antagonists for controlled ovarian stimulation (COS) were only recently introduced into China. The efficacy and safety of the GnRH antagonist ganirelix was assessed in a multicenter, controlled, open-label study, in which Chinese women were randomized to either ganirelix (n = 113) or a long GnRH agonist protocol of triptorelin (n = 120). The primary end point was the amount of recombinant follicle-stimulating hormone (rFSH) required to meet the human chorionic gonadotropin criterion (three follicles ≥17 mm). The amount of rFSH needed was significantly lower for ganirelix (1272 IU) vs. triptorelin (1416 IU; P< 0.001). Ongoing pregnancy rates per started cycle were 39.8% (ganirelix) and 39.2% (triptorelin). Although both treatments were well tolerated, cancellation due to risk of ovarian hyperstimulation syndrome (OHSS) was less frequent with ganirelix (1.8%) than triptorelin (7.5%) (P = 0.06). Less rFSH was needed in the ganirelix protocol than the long GnRH agonist protocol, with fewer reported cases of OHSS and similar pregnancy rates.     

A Patient Friendly Corifollitropin Alfa Protocol without Routine Pituitary Suppression in Normal Responders

The release of corifollitropin alfa simplifies daily injections of short-acting recombinant follicular stimulating hormone (rFSH), and its widely-used protocol involves short-acting gonadotropins supplements and a fixed GnRH antagonist regimen, largely based on follicle size. In this study, the feasibility of corifollitropin alfa without routine pituitary suppression was evaluated. A total of 288 patients were stimulated by corifollitropin alfa on cycle day 3 following with routine serum hormone monitoring and follicle scanning every other day after 5 days of initial stimulation, and a GnRH antagonist (0.25 mg) was only used prophylactically when the luteinizing hormone (LH) was ≧ 6 IU/L (over half of the definitive LH surge). The incidence of premature LH surge (≧ 10 IU/L) was 2.4% (7/288) before the timely injection of a single GnRH antagonist, and the elevated LH level was dropped down from 11.9 IU/L to 2.2 IU/L after the suppression. Two hundred fifty-one patients did not need any antagonist (87.2% [251/288]) throughout the whole stimulation. No adverse effects were observed regarding oocyte competency (fertilization rate: 78%; blastocyst formation rate: 64%). The live birth rate per OPU cycle after the first cryotransfer was 56.3% (161/286), and the cumulative live birth rate per OPU cycle after cyrotransfers was 69.6% (199/286). Of patients who did and did not receive GnRH antagonist during stimulation, no significant difference existed in the cumulative live birth rates (78.4% vs. 68.3%, p = 0.25). The results demonstrated that the routine GnRH antagonist administration is not required in the corifollitropin-alfa cycles using a flexible and hormone-depended antagonist regimen, while the clinical outcome is not compromised. This finding reveals that the use of a GnRH antagonist only occasionally may be needed.     

Alterations in hypophysial responsiveness to synthetic GnRH at different postpartum intervals in Murrah buffalo (Bubalus bubalis )

The objective of this study was to investigate the hypophysial responsiveness to GnRH at different intervals post partum in Murrah buffalo. Plasma LH and FSH levels were measured at 1 h before and upto 6 h subsequent to the administration of GnRH (1 ug/kg body weight) or saline on Days 2, 20 and 35 post partum in 2 groups of buffalo (n=4 each). Plasma progesterone levels were measured in samples collected once daily from Day 3 to Day 46 post partum. Pretreatment basal LH levels exhibited a progressive increase from Day 2 through Day 35 post partum, while the basal FSH levels increased only until Day 20 post partum. Following a highly subdued LH response to GnRH on Day 2 post partum, a 408% increase (P < 0.01) was observed in the total LH released in response to GnRH on Day 20 post partum, followed by a 20% reduction (non-significant) over Days 20 to 35 post partum. The interval from parturition was highly correlated with total LH released (r = 0.711, P < 0.01). Unlike LH, a substantial amount of FSH was released following GnRH treatment on Day 2 post partum, which was not significantly different from the FSH response on Days 20 and 35 post partum. The LH and FSH response to GnRH was not significantly different between animals in which luteal activity resumed and in those which showed no luteal activity post partum. While pointing to a dramatic enhancement in the hypophysial responsiveness to GnRH between Days 2 and 20 post partum, these results suggest that pituitary responsiveness to GnRH does not appear to be the limiting factor for resumption of estrous cycles by Day 35 post partum in Murrah buffalo.     

Effect of hCG priming on embryonic development of immature oocytes collected from unstimulated women with polycystic ovarian syndrome

ABSTRACT: Backgroud: The effect of hCG priming on oocyte maturation and subsequently outcome in IVM cycles has remained a debated issue. A randomized controlled study was performed to investigate whether or not hCG priming prior to oocyte aspiration can improve the developmental competence of immature oocytes from unstimulated ovaries in women with polycystic ovarian syndrome (PCOS). MethodsEighty two patients with PCOS underwent IVM cycles. Each patient was randomly assigned to the hCG-primed (10,000 IU) or non-primed groups 36-38 hours before oocyte retrieval depending on the computerized random table. After the oocytes had in vitro matured, fertilizationculture and embryo transfer were performed. ResultsThe average number of cumulus-oocyte complexes (COCs) recovered was 13.80 and 14.35 in the hCG-primed and non-primed groups, respectively (p>0.05). The maturation rate of COCs was significantly improved in the hCG-primed group (55.43% vs. 42.29%; p<0.05). The fertilization and cleavage rates were comparable between the groups. The hCG-primed and non-primed groups did not differ with respect to the clinical pregnancy (37.50% vs. 50.00%), live birth (22.50% vs. 30.95%), and implantation rates (32.86% vs. 32.56%). The pregnancy losses was 6 (40.00%) of 15 clinical pregnancies in the hCG-primed groupand 8 (38.10%) of 21 clinical pregnancies in the non-primed group. CONCLUSIONS: While a significant improvement in the nuclear maturation rate of immature oocytes was observed in hCG-primed IVM cycles with PCOS patients, the use of hCG prior to oocyte retrieval did not improve the subsequent embryo developmental competence. The high rate of pregnancy loss in IVM cycles should receive more attention.     

Effect of season on luteal activity during the post partum period of dairy cows in temperate areas

Seasonal effects on luteal activity during post partum were evaluated in two consecutive studies in 253 dairy cows in Northern Italy. In study 1, plasma progesterone concentrations were determined on days 14, 21, 28, 35, 42, 49 and 56 post partum and in study 2 cows were synchronized and inseminated at a fixed time using two regimes based on the 'Ovsynch' protocol. Study 1: Animals were classified as luteal (progesterone >1.5 ng/ml in at least two consecutive samples) or non-luteal (progesterone <1.5 ng/ml in all samples). The proportion of cows without luteal activity from calving to day 56 post partum was 47/253 (18.5%). Of the 47 cows without luteal activity, 42 (89%) were detected during the warm months of the year and five were detected during the cold months of the year, and the effect of season was highly significant (P < 0.001). Study 2: Three study groups were established; control (CONT, untreated cows, n = 92), GPG (cows receiving gonadotropin-releasing hormone (GnRH) on day 0, PGF2α on day 7 followed by a second dose of GnRH 24 h later, n = 80); and HPH (the same as the GPG group, but with human chorionic gonadotropin (hCG) substituted for GnRH, n = 81). In the GPG and HPH groups, cows were inseminated 16 to 22 h after the second GnRH or hCG injection. Untreated cows were inseminated at first estrus after a voluntary weaning period. Because the effects of the GPG and HPH regimes on pregnancy rate were not significantly different, data were pooled into a single treatment group (TREAT). Pregnancy rates during the warm months of the year were 16% and 15% at first service and 65% and 66% at day 135 post partum for CONT and TREAT groups, respectively. Pregnancy rates during the cold months of the year were 36% and 38% at first service and 72% and 76% at day 135 post partum for CONT and TREAT groups, respectively. There was an effect of season (P < 0.05) but not of treatment on pregnancy rate. Treatment reduced the number of days from calving to conception during both the cold (101 ± 3.2 v. 121 ± 3.1 days; P < 0.001) and warm seasons (122 ± 3.2 v. 145 ± 3.1 days; P < 0.001). In conclusion, the present study shows that (i) heat stress during the warm season can compromise luteal activity and (ii) that regimes based on the Ovsynch protocol did not improve pregnancy rate at first service or by 135 post partum, but they had a positive effect on the calving-to-conception interval.     

Suppression of pulsatile luteinizing hormone secretion by gonadotrophin-releasing hormone antagonist does not affect episodic progesterone secretion or corpus luteum function in ewes.

Progesterone secretion has been observed to be episodic in the late luteal phase of the oestrous cycle of ewes and is apparently independent of luteinizing hormone (LH). This study investigated the effects of suppressing the pulsatile release of LH in the early or late luteal phase on the episodic secretion of progesterone. Six Scottish Blackface ewes were treated i.m. with 1 mg kg-1 body weight of a potent gonadotrophin-releasing hormone (GnRH) antagonist on either day 4 or day 11 of the luteal phase. Six ewes received saline at each time and acted as controls. Serial blood samples were collected at 10 or 15 min intervals between 0 and 8 h, 24 and 32 h, and 48 and 56 h after GnRH antagonist treatment and daily from oestrus (day 0) of the treatment cycle for 22 days. Oestrous behaviour was determined using a vasectomized ram present throughout the experiment. Progesterone secretion was episodic in both the early and late luteal phase with a frequency of between 1.6 and 3.2 pulses in 8 h. The GnRH antagonist abolished the pulsatile secretion and suppressed the basal concentrations of LH for at least 3 days after treatment. This suppression of LH, in either the early or late luteal phase, did not affect the episodic release of progesterone. Daily concentrations of progesterone in plasma showed a minimal reduction on days 11 to 14 after GnRH antagonist treatment on day 4, although this was significant (P < 0.05) only on days 11 and 13. There was no effect of treatment on day 11 on daily progesterone concentration, and the timing of luteolysis and the duration of corpus luteum function was unaffected by GnRH antagonist treatment on either day 4 or day 11. These results indicate that the episodic secretion of progesterone during the luteal phase of the oestrous cycle in ewes is independent of LH pulses and normal progesterone secretion by the corpus luteum can be maintained with minimal basal concentrations of LH.     

Aspects of in vivo oocyte production,blastocyst development,and embryo transfer in the cat

A brief overview of the progress made during the past approximately 40 years on the development of methods for in vitro production of cat embryos and intra- and interspecies embryo transfer is described. The presentation is focused primarily on research done over the past 30 years at the Cincinnati Zoo (1980–1995) and at the Audubon Nature Institute, New Orleans (1996–present) beginning with original studies on determining optimal doses of porcine FSH for ovarian stimulation and uterine embryo recovery, cryopreservation, and transfer. A key early finding was the ability of cats to respond to multiple gonadotropin (porcine FSH) treatments by repeated stimulation of follicular development. With a ≥6-month interval between FSH treatments, over the past 15 years (1998–2013), we have done 1603 laparoscopic oocyte retrievals on 337 cats and recovered >38,000 mature oocytes (mean = 24.1 per laparoscopic oocyte retrieval). The limited information available on in vivo blastocyst development in the cat during the latter portion of the preimplantation period (approximately Days 8 to 12 after coitum or approximately Days 7 to 11 after ovulation) was assembled for the purpose of comparing and contrasting it with the growth, expansion, and zona functioning of in vitro-derived blastocysts. Also, results of transferring morulae and/or blastocysts into synchronous recipients are described to emphasize evidence that appears to allude to an essential role for an intact zona pellucida in successful implantation and subsequent development in the cat. Until 2003, our in vitro-derived embryos were transferred into the uterine horns of recipients to determine the feasibility of producing offspring from such primary methods as IVF, intracytoplasmic sperm injection, SCNT, and embryo cryopreservation. With the exception of SCNT embryos, pregnancy rates were satisfactory, but embryo survival rates were not. Subsequently, after finding that SCNT embryo survival rate could be improved using laparoscopic transfer of early cleavage stage embryos into the oviduct, we applied the technique to embryos derived using IVF with sex-sorted sperm, oocyte vitrification, and embryo cryopreservation. Overall, a pregnancy rate of 67% (14/21) has resulted. Most recently, with the oviductal embryo transfer technique, two litters of Black-Footed cat kittens have been born from intra- and interspecies transfer of cryopreserved embryos.     

Effects of a single injection of hCG or GnRH agonist on day 12 post mating on fetal growth and reproductive performance of sheep

Reproductive performance and fetal growth were determined when hCG (150 i.u. Pregnyl; n=44), GnRH (4 microg synthetic GnRH agonist, buserelin, Receptal; n=43) or saline (control, n=45) was administered (i.m.) to ewes on day 12 post mating during the breeding season. A total of 12 ewes was slaughtered on day 45 of pregnancy (four from each treatment group). Non-return rate and lambing rate were higher for ewes in the hCG (0.89 and 84%) and GnRH treated groups (0.86 and 79%) than for ewes in the control (0.69 and 62%) group (P<0.05). The ewes in the hCG and GnRH groups also had more twins (P<0.05). Birth weights of these twin lambs in the hCG and GnRH groups were heavier than those in the control group (P<0.05), but this difference had disappeared at weaning 60 days later. Lamb mortality was similar among treatment groups resulting in a higher number of lambs weaned in the hCG and GnRH groups. The ovarian weights and the number of corpora lutea (CL) and luteal weights of ewes slaughtered on day 45 of pregnancy were greater (P<0.05) in the hCG and GnRH treated groups than those measured in the control group. Administration of hCG on day 12 post mating increased gravid uterus weight, crown-rump-length (CRL), chorioallantois weight and total cotyledon weight (P<0.05) of conceptuses recovered on day 45 of pregnancy compared to the control group. The weights of caruncules (P<0.05) and placenta (P<0.01) were higher in conceptuses of both the hCG and GnRH groups. The weights of fetuses in the hCG group were higher than those in both the GnRH and control groups (P<0.05). In conclusion, both hCG and GnRH administration improved reproductive performance of ewes when administered on day 12 post mating. However, hCG and GnRH appeared to act differently on embryo survival because only hCG administration increased fetal growth.