A review of luteinising hormone and human chorionic gonadotropin when used in assisted reproductive technology

FSH/LH co-stimulation in Advanced Maternal Age (AMA) and hypo-responder patients - Arabian gulf delphi consensus group

Background

In a global effort to assess expert perspectives on the use of recombinant gonadotropins, recombinant human luteinizing hormone (r-hLH) and recombinant human follicle-stimulating hormone (r-hFSH), a consensus meeting was held in Dubai. The key aim was to address three critical questions: What are the factors that influence follicle response to gonadotropins? Which categories of patients are most likely to benefit from LH supplementation? And what are the optimal management strategies for these patients?

Methods

A panel of thirty-six experts reviewed and refined the initial statements and references proposed by the Scientific Coordinator. Consensus was defined as agreement or disagreement by more than two-thirds (66%) of the panel members for each statement.

Results

Thirty-five statements were formulated, of which thirty-one reached consensus. For patients with Hypo-Response to Gonadotropin Stimulation (20 statements), all identified risk factors, including advanced age, high BMI, and chronic conditions, achieved unanimous agreement. Diagnostic approaches, such as the inclusion of POSEIDON criteria and hormone level monitoring, were endorsed by the majority, with over 90% agreement. Management strategies, particularly individualized stimulation protocols and optimized scheduling, garnered broad consensus, with only one statement falling short of the threshold. Additionally, in cases of severe FSH and LH deficiency, combining r-hFSH with r-hLH was found to improve pregnancy rates and cost efficiency compared to human menopausal gonadotropin (hMG). For patients with Advanced Maternal Age (AMA) (15 statements), there was strong agreement on the use of oral contraceptive pills and estrogen priming. Recommendations concerning antagonist protocols and dosing of r-hLH and r-hFSH also achieved high levels of consensus. Significant agreement supported r-hLH supplementation and a tailored approach to luteal phase support. However, there were mixed opinions on the route of progesterone administration, with some experts expressing neutral or disagreeing views. Despite these differences, unanimous consensus was reached on markers of treatment success, particularly live birth rates, pregnancy rates, and embryo development, underscoring the importance of these outcomes in evaluating treatment efficacy.

Conclusion

This consensus provides a practical clinical perspective to a wide range of global professionals on the strategies employed during key phases of Assisted Reproductive Technology (ART) treatment. To further improve outcomes, incorporating additional clinical insights on ART approaches, alongside existing guidelines and policies, may offer valuable guidance for optimizing patient care.

GnRH agonist-only trigger, compared to dual trigger, reduces oocyte retrieval rate in high responders without affecting cumulative live birth rate

Introduction

This study compared, in high responders undergoing IVF treatment, GnRH agonist-only trigger and dual trigger on oocyte retrieval rate and cumulative live birth rate (LBR). The aim was to determine if the GnRH agonist-only triggers had provided outcomes comparable to dual trigger, while minimizing the risk of ovarian hyperstimulation syndrome (OHSS).

Materials and methods

A retrospective, matched case-control study was conducted at Taichung Veterans General Hospital, Taiwan, including women who underwent IVF/ICSI between January 1, 2014, and December 31, 2022. Inclusion criteria were: GnRH antagonist protocol and estrogen level >3,000 pg/ml on trigger day. Exclusion criteria were: immune/metabolic diseases, donated oocytes, and mixed stimulation cycles. Propensity score matching was applied to balance age, AMH level, and oocyte number between the GnRH agonist-only and dual trigger groups. Outcomes were analyzed for patients who had complete treatment cycles, focusing on oocyte retrieval rate and cumulative LBR.

Results

We analyzed 116 cycles in the agonist-only group, and 232 cycles in the dual trigger group. No inter-group difference was found in their age, BMI, and AMH levels. The dual trigger group had a higher oocyte retrieval rate (93% vs. 80%; p <0.05), while fertilization rates, blastocyst formation rates, and cumulative LBR were comparable. Notably, no OHSS cases had been reported in the GnRH agonist-only group, compared with 7 cases in the dual trigger group.

Conclusion

GnRH agonist-only triggers resulted in a lower oocyte retrieval rate compared to dual triggers but did not significantly affect cumulative LBR in high responders. This approach effectively reduces OHSS risk without compromising pregnancy outcomes, making it a preferable option in freeze-all strategies, despite a longer oocyte pick-up duration and a medium cost. GnRH agonist-only trigger, however, may not be suitable for fresh embryo transfers or patients with low serum LH levels on trigger day.

Spermatogenesis in mouse testicular organoids with testis-specific architecture, improved germ cell survival and testosterone production

This study presents a biphasic approach to overcome the limitations of current testicular organoid (TO) cultures, including histological heterogeneity, germ cell loss and absence of spermatogenesis. Agarose microwells were utilized to create TOs from prepubertal C57BL/6 J testicular cells. First emphasis was on improving germ cell survival during the initial 2-week reorganization phase by comparingα-MEM + 10% knockout serum replacement (KSR) medium, known to support TO generation in mice, to three optimized media (1-3). Cell densities and culture dynamics were also tested to recreate histological resemblance to testes. After optimizing germ cell survival and cell organization, the effect of growth factors and immunomodulation through CD45+immune cell depletion or dexamethasone (DEX) supplementation were assessed for enhancing spermatogenesis during the subsequent differentiation phase. Testicular cells self-reorganized into organoids resembling the testicular anatomical unit, characterized by one tubule-like structure surrounded by interstitium. Media 1-3 proved superior for organoid growth during the reorganization phase, with TOs in medium 3 exhibiting germ cell numbers (7.4% ± 4.8%) comparable to controls (9.3% ± 5.3%). Additionally, 37% ± 30% demonstrated organized histology from 32 × 103cells under static conditions. Switching toα-MEM + 10% KSR during the differentiation phase increased formation efficiency to 85 ± 7%, along with elevated germ cell numbers, testosterone production (3.1 ± 0.9 ng ml-1) and generation ofγ-H2AX+spermatid-like cells (steps 8-11, 1.2% ± 2.2% of the total). Adding differentiation factors to theα-MEM increased spermatid-like cell numbers to 2.9% ± 5.9%, confirmed through positive staining for CREM, transition protein 1, and peanut agglutinin. Although, these remained diploid with irregular nuclear maturation. DEX supplementation had no additional effect, and immune cell depletion adversely impacted TO formation. The manipulability of TOs offers advantages in studying male infertility and exploring therapies, with scalability enabling high-throughput chemical screening and reducing animal usage in reproductive toxicity and drug discovery studies.

Use of chorionic gonadotropins during lactation to optimize postpartum sow reproductive performance: a review

Treating lactating sows with chorionic gonadotropins may allow controlling their post-weaning reproductive function, despite the occurrence of anestrous during lactation. This article reviews the potential effectiveness of treatment with both equine and human chorionic gonadotropins (eCG and hCG, respectively) during lactation on the control of estrus expression and ovulation in weaned sows. The use of 1,000 IU hCG at 24 and 48 h postpartum may induce ovulation in the treated sows, but the ovulation rate may be variable. Pregnancy rates may be improved with combined treatment after the second week of lactation with both chorionic gonadotropins: 1,500 IU eCG plus 500 - 1,000 hCG; or 1,000 IU eCG plus 1,000 IU hCG. Treatment with eCG (1,000 - 2,000 IU) at the end of lactation may result in acceptable estrus expression and ovulation rates, although with marginal benefit for pregnancy rates. The subsequent response to treatments with chorionic gonadotropins during lactation is likely influenced by the treatment period, the suckling frequency during lactation, and the boar exposure during the weaning-to-estrus interval. A better understanding of the efficiency of such steroid-free treatments is increasingly relevant due to the constraints of the use of steroid hormones in livestock reproductive management.

Mitochondrial Dynamics as Potential Modulators of Hormonal Therapy Effectiveness in Males

Worldwide the incidence of andrological diseases is rising every year and, together with it, also the interest in them is increasing due to their strict association with disorders of the reproductive system, including impairment of male fertility, alterations of male hormones production, and/or sexual function. Prevention and early diagnosis of andrological dysfunctions have long been neglected, with the consequent increase in the incidence and prevalence of diseases otherwise easy to prevent and treat if diagnosed early. In this review, we report the latest evidence of the effect of andrological alterations on fertility potential in both young and adult patients, with a focus on the link between gonadotropins' mechanism of action and mitochondria. Indeed, mitochondria are highly dynamic cellular organelles that undergo rapid morphological adaptations, conditioning a multitude of aspects, including their size, shape, number, transport, cellular distribution, and, consequently, their function. Since the first step of steroidogenesis takes place in these organelles, we consider that mitochondria dynamics might have a possible role in a plethora of signaling cascades, including testosterone production. In addition, we also hypothesize a central role of mitochondria fission boost on the decreased response to the commonly administrated hormonal therapy used to treat urological disease in pediatric and adolescent patients as well as infertile adults.

Gonadotropins as pharmacological agents in assisted reproductive technology and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrinopathy associated with subfertility/infertility and pregnancy complications. Most PCOS women opt for assisted reproductive technologies (ART) for successful conception; however, optimization of the relative doses of the gonadotropins [follicle-stimulating hormone (FSH), luteinizing hormone (LH)/human chorionic gonadotropin (hCG)] for appropriate steroidogenesis, without causing ovarian hyperstimulatory syndrome (OHSS), is challenging. Embryonic factors probably do not contribute to pregnancy loss in PCOS women, albeit hormonal imbalance impairs the metabolic microenvironment critical for oocyte maturation and endometrial receptivity. Certain clinical studies have confirmed the role of metabolic corrections in increasing the rate of pregnancy in PCOS women. This review focuses on the impact of untimely high LHCGR and/or LH levels on oocyte/embryo quality, pregnancy outcomes in ART, and exploring LHCGR as a potential drug target in PCOS women.

Comparison of dual-trigger and human chorionic gonadotropin-only trigger among polycystic ovary syndrome couples who underwent controlled ovarian stimulation and intrauterine insemination: A retrospective cohort study

The dual-trigger regime, consisting of gonadotrophin releasing hormone agonist and human chorionic gonadotropin (HCG), has been shown to offer advantage over the HCG-only trigger regime. However, little is known about the influence of dual-trigger or HCG-only trigger regime on the reproductive outcome of polycystic ovary syndrome (PCOS) couples undergoing controlled ovarian stimulation (COS) and intrauterine insemination (IUI). A total of 404 cycles of COS and IUI treatments from couples with PCOS were enrolled, and divided, according to the regime of trigger, into dual-trigger group (n = 109, 0.1-0.2 mg gonadotrophin releasing hormone agonist plus 6000 IU HCG) and HCG-only group (n = 295, 10,000 IU HCG or 250 μg recombinant HCG). Baseline characteristics of the 2 groups were comparable (all P > .05). In dual-trigger group, live birth rate, clinical pregnancy rate and β -HCG positive rate were all higher as compared to the HCG-only group (20.18% vs 18.98%, 25.69% vs 23.39% and 28.44% vs 25.08% respectively), despite the differences failed to achieve statistical significances (all P > .05). Moreover, early miscarriage rate and multiple pregnancy rate of the dual-trigger group were lower than those of the HCG-only group (17.86% vs 18.84% and 3.57% vs 7.25% respectively), although no statistical significances were found (all P > .05). Additionally, logistic regression analysis revealed that age contributed significantly to the live birth of couples with PCOS ( P = .043, OR = 0.900). Dual-trigger regime for oocyte maturation seems to associate with beneficial improvements in reproductive outcomes of PCOS couples undergoing COS and IUI. Instead of HCG-only trigger, dual-trigger regime might be an alternative option in COS and IUI cycles for couples with PCOS.

Synthetic Peptides in Doping Control: A Powerful Tool for an Analytical Challenge

Peptides are very diverse molecules that can participate in a wide variety of biological processes. In this way, peptides are attractive for doping, since these molecules can activate or trigger biological processes that can improve the sports performance of athletes. Peptide molecules are found in the official World Anti-Doping Agency lists, mainly in sections S2, S4, and S5. In most cases, these molecules have a very short half-life in the body and/or are identical to natural molecules in the body, making it difficult to analyze them as performance-enhancing drugs. This article reviews the role of peptides in doping, with special emphasis on the peptides used as reference materials, the pretreatment of samples in biological matrices, the instrumentation, and the validation of analytical methodologies for the analysis of peptides used in doping. The growing need to characterize and quantify these molecules, especially in complex biological matrices, has generated the need to search for robust strategies that allow for obtaining sensitive and conclusive results. In this sense, strategies such as solid phase peptide synthesis (SPPS), seeking to obtain specific peptides, metabolites, or isotopically labeled analogs, is a key tool for adequate quantification of different peptide molecules in biological matrices. This, together with the use of optimal methodologies for sample pretreatment (e.g., SPE or protein precipitation), and for subsequent analysis by high-resolution techniques (mainly hyphenated LC-HRMS techniques), have become the preferred instrumentation to meet the analytical challenge involved in the analysis of peptides in complex matrices.

Tumors of the central nervous system among women treated with fertility drugs: a population-based cohort study

PURPOSE

To investigate the association between fertility drugs and tumors of the central nervous system (CNS).

METHODS

This cohort study was based on The Danish Infertility Cohort and included 148,016 infertile women living in Denmark (1995-2017). The study cohort was linked to national registers to obtain information on use of specific fertility drugs, cancer diagnoses, covariates, emigration, and vital status. Cox proportional hazard regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all CNS tumors and separately for gliomas, meningiomas and diverse benign tumors of the brain and other parts of the CNS.

RESULTS

During a median 11.3 years of follow-up, 328 women were diagnosed with CNS tumors. No marked associations were observed between use of the fertility drugs clomiphene citrate, gonadotropins, gonadotropin-releasing hormone receptor modulators and progesterone and CNS tumors. However, use of human chorionic gonadotropin was associated with a decreased rate of meningiomas (HR 0.49 95% CI 0.28-0.87). No clear associations with CNS tumors were observed according to time since first use or cumulative dose for any of the fertility drugs.

CONCLUSION

No associations between use of most types of fertility drugs and CNS tumors were observed. However, our findings only apply to premenopausal women and additional studies with longer follow-up time are necessary.

The Effects of Separate and Combined Treatment of Male Rats with Type 2 Diabetes with Metformin and Orthosteric and Allosteric Agonists of Luteinizing Hormone Receptor on Steroidogenesis and Spermatogenesis

In men with type 2 diabetes mellitus (T2DM), steroidogenesis and spermatogenesis are impaired. Metformin and the agonists of luteinizing hormone/human chorionic gonadotropin(hCG)-receptor (LH/hCG-R) (hCG, low-molecular-weight allosteric LH/hCG-R-agonists) can be used to restore them. The aim was to study effectiveness of separate and combined administration of metformin, hCG and 5-amino-N-tert-butyl-2-(methylsulfanyl)-4-(3-(nicotinamido)phenyl)thieno[2,3-d]pyrimidine-6-carboxamide (TP3) on steroidogenesis and spermatogenesis in male rats with T2DM. hCG (15 IU/rat/day) and TP3 (15 mg/kg/day) were injected in the last five days of five-week metformin treatment (120 mg/kg/day). Metformin improved testicular steroidogenesis and spermatogenesis and restored LH/hCG-R-expression. Compared to control, in T2DM, hCG stimulated steroidogenesis and StAR-gene expression less effectively and, after five-day administration, reduced LH/hCG-R-expression, while TP3 effects changed weaker. In co-administration of metformin and LH/hCG-R-agonists, on the first day, stimulating effects of LH/hCG-R-agonists on testosterone levels and hCG-stimulated expression of StAR- and CYP17A1-genes were increased, but on the 3-5th day, they disappeared. This was due to reduced LH/hCG-R-gene expression and increased aromatase-catalyzed estradiol production. With co-administration, LH/hCG-R-agonists did not contribute to improving spermatogenesis, induced by metformin. Thus, in T2DM, metformin and LH/hCG-R-agonists restore steroidogenesis and spermatogenesis, with metformin being more effective in restoring spermatogenesis, and their co-administration improves LH/hCG-R-agonist-stimulating testicular steroidogenesis in acute but not chronic administration.

A Randomized Controlled Trial on the Efficacy and Safety of Low-Dose hCG in a Short Protocol with GnRH Agonist and Ovarian Stimulation with Recombinant FSH (rFSH) During the Follicular Phase in Infertile Women Undergoing ART

Τhis study aims to investigate whether the addition of low-dose hCG throughout stimulation in infertile women undergoing IVF improves IVF outcome parameters. This is a prospective, multicenter, randomized, double-blind, placebo-controlled, Phase IIIb clinical study, conducted in three university IVF units. We studied whether the addition of 100 IU hCG/day to a short GnRH agonist IVF protocol from the onset of the follicular phase (group 1, n=40) or placebo (group 2, n=41) had any impact on the number of high-quality transferred embryos at day 2 and clinical pregnancy rates. The comparison encompassed descriptive statistics, and univariate and multivariate analyses. Concerning the primary outcomes, we found no differences in both the number of high-quality embryos (≥2) at day 3 [21/40 (52.5%) vs. 14/41 (34.2%), p=0.095] and clinical pregnancy rates [10/40 (25%) vs. 10/41 (24.4%), p=0.949], respectively. Similarly, there were no differences concerning the secondary outcomes preset for this trial. According to the results of the multivariate logistic regression analysis, no significant associations were noted for primary outcomes (clinical pregnancy: adjusted OR=0.89, 95% CI: 0.29–2.75; (≥2 excellent quality embryos at day 3: adjusted OR=0.54, 95% CI: 0.21–1.42, with group 1 set as reference category); similarly, no differences were noted with respect to secondary outcomes, except from the increased odds of ≥2 poor-quality embryos at day 3 occurring in group 2 (adjusted OR= 11.69, 95%CI: 1.29–106.19). The addition of low-dose hCG to a short GnRH agonist protocol for IVF does not improve the number of top-quality embryos and clinical pregnancy rates.

Supplementation with human menopausal gonadotropin in the gonadotropin-releasing hormone antagonist cycles of women with high AMH: Pregnancy outcomes and serial hormone levels

OBJECTIVE

To evaluate the value of using both HMG and recombinant FSH (r-FSH) in the GnRH antagonist protocol for women with high AMH.

MATERIALS AND METHODS

This retrospective, single-center cohort study was conducted from January 2013 to December 2018. Of 277 GnRH antagonist IVF/ICSI cycles in women with anti-Mullerian hormone (AMH) ≥5 μg/L, 170 cycles receiving the combination of r-FSH and HMG (77 with HMG added at the beginning of the GnRH antagonist cycle and 93 with HMG added after GnRH antagonist administration) and 107 cycles receiving r-FSH alone were analyzed. The dynamic hormone profiles and embryonic and clinical outcomes of the patients were evaluated.

RESULTS

We observed significantly lower serum LH levels in the r-FSH + HMG groups during ovarian stimulation. The serum estradiol and progesterone levels were lower in the r-FSH + HMG groups on the trigger day. Nevertheless, there were no significant differences with respect to the number of oocytes retrieved, maturation, fertilization, blastocyst formation rate or ovarian hyperstimulation syndrome (OHSS). The implantation and live birth rates were increased in the r-FSH + HMG groups compared with the r-FSH alone group, with no statistical significance.

CONCLUSIONS

HMG for LH supplementation in the GnRH antagonist protocol for patients with high AMH is not significantly superior to r-FSH alone in terms of ovarian response and pregnancy outcome. Nevertheless, HMG supplementation might be appropriate for women with an initially inadequate response to r-FSH or intracycle LH deficiency.

Double HCG trigger improves recovery of oocytes in women with a paucifollicular response to ovarian stimulation: A pilot study

OBJECTIVE

To examine whether adding a second HCG trigger, 12.5 h after the first (36.5 h before ovarian puncture), can facilitate recovery of oocytes in women with a paucifollicular response to ovarian stimulation.

METHODS

A total of 85 women aged 35-42 years, with a paucifollicular response to ovarian stimulation and who had experienced a total failure of oocyte recovery after the standard HCG ovulation trigger 36.5 h before ovarian puncture, were subsequently treated by the same protocol but with the addition of a second HCG trigger 12.5 h later. The recovered oocytes were inseminated by intracytoplasmic sperm injection (ICSI) and all available embryos were transferred 3 days later.

RESULTS

The double trigger enabled recovery of cumulus oophorus cells from most of the follicles in the women who experienced failure of total recovery of oocytes after a single trigger. Fifteen patients became pregnant, and no signs of ovarian hyperstimulation syndrome were observed. Nine women delivered a healthy child.

CONCLUSION

In women aged 35-42 years with a paucifollicular response to ovarian stimulation, a double HCG trigger appears to improve the rate of oocyte recovery. The conclusion of this pilot study needs to be confirmed by larger prospective trials.

Kisspeptin-54 injection induces a physiological luteinizing hormone surge and ovulation in mice

Intraperitoneal injection of kisspeptin-54 induces a surge-like release of luteinizing hormone that stimulates ovulation in mice.

Two human menopausal gonadotrophin (hMG) preparations display different early signaling in vitro

Commercial hMG drugs are marketed for the treatment of infertility and consist of highly purified hormones acting on receptors expressed in target gonadal cells. Menopur® and Meriofert® are combined preparation of FSH and hCG and are compared in vitro herein. To this purpose, the molecular composition of the two drugs was analyzed by immunoassay. The formation of FSH receptor and LH/hCG receptor (FSHR; LHCGR) heteromer, intracellular Ca2+ and cAMP activation, β-arrestin 2 recruitment and the synthesis of progesterone and estradiol were evaluated in transfected HEK293 and human primary granulosa lutein cells treated by drugs administered within the pg-mg/ml concentration range. Molecular characterization revealed that Meriofert® has a higher FSH:hCG ratio than Menopur® which, in turn, displays the presence of LH molecules. While both drugs induced similar FSHR-LHCGR heteromeric formations and intracellular Ca2+ increase, Meriofert® had a higher potency than Menopur® in inducing a cAMP increase. Moreover, Meriofert® revealed a higher potency than Menopur® in recruiting β-arrestin 2, likely due to different FSH content modulating the tridimensional structure of FSHR-LHCGR-β-arrestin 2 complexes, as evidenced by a decrease in bioluminescence resonance energy transfer signal. This drug-specific activation of intracellular signaling pathways is consistent with the molecular composition of these preparations and impacts downstream progesterone and estradiol production, with Menopur® more potent than Meriofert® in inducing the synthesis of both the steroids. These findings are suggestive of distinct in-vivo activities of these preparations, but require cautious interpretation and further validation from clinical studies.

Serum nesfatin-1 is associated with testosterone and the severity of erectile dysfunction

This cross-sectional study aimed to evaluate serum nesfatin-1 concentrations in patients with erectile dysfunction (ED). Patients with ED were selected from the Department of Urology of the Second Affiliated Hospital of Anhui Medical University. The International Index of Erectile Function-5 (IIEF-5) was used to evaluate the severity of ED. Serum nesfatin-1 and gonadal hormone levels, including luteinising hormone (LH), follicle-stimulating hormone (FSH) and testosterone were measured. The IIEF-5 scores (t = -21.034, p < .001) and nesfatin-1 levels (t = -7.043, p < .001) in patients with ED were significantly lower than in healthy controls. Moreover, patients with ED showed decreased testosterone levels (t = -3.478, p = .001), whereas there were no significant differences in serum levels of FSH (t = -0.088, p = .930) and LH (t = 1.114, p = .270) between the two groups. Furthermore, positive relationships were found between serum nesfatin-1 and testosterone concentrations (r = .742, p = .001) and IIEF-5 scores (r = .395, p = .009) in ED patients. Additionally, based on receiver operating characteristic curve analysis, the area under curve for nesfatin-1 was 0.884 with 83.3% sensitivity and 81.4% specificity in discriminating ED patients from healthy controls. The decrease in serum nesfatin-1 level may be related to testosterone and the severity of ED.

Investigating the Optimal Time for Intrauterine Human Chorionic Gonadotropin Infusion in Order to Improve IVF Outcome: A Systematic Review and Meta-Analysis

BACKGROUND/AIM

Studies on the impact of intrauterine human Chorionic Gonadotropin (hCG) administration in order to improve the In Vitro Fertilization (IVF) outcome have yielded conflicting results. The aim of the present systematic review and meta-analysis is to investigate whether timing of intrauterine hCG administration prior to embryo transfer affects its efficiency.

MATERIALS AND METHODS

A systematic search of the literature on Pubmed/Medline, Embase and Cochrane databases was performed. Only Randomized Control Trials were included in this meta-analysis.

RESULTS

Live birth rates were not improved following hCG administration (RR=1.13, 95%CI=0.88-1.46, p=0.34) in the pooled results. Combined live birth and ongoing pregnancy rates were borderline statistically significant following hCG administration (RR=1.27, 95%CI=1.00-1.62, p=0.05). Following subgroup analysis regarding live birth and ongoing pregnancy rates, only the 5-12 minutes prior to the embryo transfer group reported a statistically significant improvement.

CONCLUSION

Intrauterine infusion of hCG within an IVF-Intracytoplasmic Sperm Injection (ICSI) cycle improves outcome only when administered 5-12 min prior to embryo transfer.

Conservation of Steroidogenic Effect of the Low-Molecular-Weight Agonist of Luteinizing Hormone Receptor in the Course of Its Long-Term Administration to Male Rats

Abstract-It was shown that the thienopyrimidine derivative TP03, a low-molecular-weight agonist of the luteinizing hormone receptor (LHR), during the treatment of male rats for 7 days steadily increased the production of testosterone (T), whose elevated level was retained for 7 days, and increased the expression of the gene for LHR, which indicates the maintenance of the sensitivity of Leydig cells to gonadotropins. At the same time, the steroidogenic effect of human chorionic gonadotropin (hCG), which significantly increased the T level on the first day of administration, was further weakened, which was accompanied by a decrease in the expression of the gene for LHR in the testes, indicating the development of resistance of Leydig cells to hCG. Along with this, in the case of hCG administration, a compensatory increase in the expression of genes of the steroidogenic enzymes, such as cytochrome P450_scc and dehydrogenase 3β-HSD, was shown in the testes, while in the case of TP03 administration this effect was absent.

Temporal expression pattern of steroid-metabolizing enzymes in bovine COC during in vitro maturation employing different gonadotropin concentrations

Steroid hormones are regulators in the fine-tuned process of follicular development. During final maturation in vivo a switch from oestradiol (E2) to progesterone (P4) dominance within the follicle is well-described. This change is accompanied by the resumption of meiosis and results in the maturation of the oocyte. It also suggests the important role of these hormones. However, present in vitro maturation (IVM) systems do not completely mimic the in vivo situation, resulting in oocytes of reduced quality. Aim of the study was to determine the temporal pattern of steroid hormone concentrations in the IVM medium of bovine cumulus-oocyte-complexes (COC) at defined time points. The influence of different gonadotropin supplementations during IVM on oocyte maturation, as well as the molecular quality of the oocytes and their corresponding cumulus cells was investigated. COCs were obtained from abattoir-derived ovaries and matured in medium added with different compounds of gonadotropins (eCG/hCG; FSH/LH, each at 0.05 IU or 0.01 IU; only FSH; without gonadotropins) employing a standard protocol without oil overlay. In experiment 1, medium, oocytes and cumulus cells were collected at different time points (0 h [control], 4 h, 8 h, 12 h, 16 h, 20 h, 24 h) after IVM in just eCG/hCG-supplemented medium. In experiment 2, medium, oocytes and cumulus cells were collected at 0 h (control) and after 24 h of IVM with all above-named supplements. The E2 concentration remained similar during IVM whereas P4 concentration increased during experiment 1. No significant changes could be determined after the addition of different gonadotropins (experiment 2). These results suggest that during IVM the temporal pattern of E2 and P4 did not correspond with the pattern during final maturation in vivo. RT-qPCR was used to assess the relative abundance of developmentally important genes in oocytes (BMP15; GDF9; ZAR1; PGR; PGRMC1/2; G6PD; StAR; ESR1/2; SULT1E1; STS; SOAT) and cumulus cells (ESR1/2; FSHR; LHCGR; CYP19A1; HSD3B1; PGR; PGRMC1/2; SULT1E1; STS; SOAT) at all collection points in both experiments. Most transcripts follow a time-regulated mRNA expression pattern during the entire in vitro maturation period. In addition, the expression of the analyzed transcripts was not influenced by the different gonadotropin supplementations during the IVM period. In all, this underlines that present conditions of IVM do not reflect the in vivo situation and require further optimisation.

'Spare' Luteinizing Hormone Receptors: Facts and Fiction

It is common opinion that maximal activation of luteinizing hormone (LH)-dependent steroidogenic signal occurs at <1% of human LH/choriogonadotropin (hCG) receptor (LHCGR) occupancy. This effect would be a consequence of an excess of receptors expressed on the surface of theca cells, resulting in a pool of LHCGRs remaining unbound (spare). This concept was borrowed from historical pharmacological studies, when discrepancies between ligand-receptor binding and dose-response curves of cAMP were evaluated by treating mouse or rat Leydig cells with hCG in vitro. Recent findings demonstrated the specificity of LH- and hCG-dependent effects, receptor heterodimerization, and differing behaviors of rodent versus human gonadotropin-responsive cells, which may help to revise the 'spare' LHCGRs concept applied to human ovarian physiology and assisted reproduction.

The non-preventive effects of human menopausal gonadotropins on ovarian tissues in Nandrolone decanoate-treated female rats: A histochemical and ultra-structural study

BACKGROUND

The follicular growth and development may be affected by abused drugs. Nandrolone decanoate (ND) as an anabolic androgenic steroid can damage the morphological and functional features of the ovary and may lead to reproductive failure.

OBJECTIVE

This study was designed to evaluate the effects of synchronized and non-synchronized administration of Human Menopausal Gonadotropins (hMG) with ND on ovarian tissue and level of sex hormones in the adult female rat.

MATERIALS AND METHODS

Forty adult female Sprague Dawley rats were divided into eight groups. The five experimental groups received 3 and/or 10 mg/kg of ND synchronized and non-synchronized with 10 IU of hMG and hMG alone. The two shams and control groups received solvents of ND and hMG. The animals' serum levels of Follicle-stimulating hormone, Luteinizing hormone, progesterone and estrogen and the weight, volume and dimensions of the ovaries were measured. The ovaries were prepared for apoptosis assessment and morphological study.

RESULTS

The ovarian volume and sex hormones in the experimental groups were decreased, but ovarian weight and dimensions didn't change. The rate of apoptosis was increased in the experimental groups as follows; a low and high dose of ND synchronized with hMG 48.80±18.70 and 65.20±14.20 respectively vs. Sham 1, 33.20±17.80, a low and high dose of ND non-synchronized with hMD 55.80±17.20 and 75.20±14.30 respectively vs. Sham 2, 31.60±32.40 groups, p˂0.01. Follicular and stromal cells were damaged in the experimental groups except for the hMG group.

CONCLUSION

Administration of ND decreased the serum level of Luteinizing hormone, Follicle-stimulating hormone, progesterone and estrogen and damaged ovarian tissue irreversibly and irreparably and hMG cannot prevent the destruction of the follicles in the adult female rats. This can be a serious warning to women who abuse ND.

Comparison of dual trigger with combination GnRH agonist and hCG versus hCG alone trigger of oocyte maturation for normal ovarian responders

OBJECTIVE

To investigate whether dual triggering of oocyte maturation with a gonadotropin-releasing hormone (GnRH) agonist and standard dose of human chorionic gonadotropin (hCG) can improve clinical outcomes for normal ovarian responders in GnRH antagonist cycles.

METHODS

The present retrospective cohort study included women aged up to 40 years with normal ovarian response who underwent in vitro fertilization and/or intracytoplasmic sperm injection under the GnRH antagonist protocol at Nanfang Hospital, China, between January 1 and December 31, 2015. Patients were grouped by whether oocyte maturation was triggered with GnRH agonist plus 5000-10 000 IU of hCG (dual trigger) or hCG alone. The primary outcome was live delivery rate.

RESULTS

There were 325 women included; 224 in the dual trigger group and 101 in the hCG alone group. The live delivery rate did not differ significantly between the groups (P=0.083). The mean number of retrieved oocytes was similar in the two groups (P=0.719), but the mean number of two-pronuclear embryos (P=0.004), the mean number of embryos available (P=0.001), and the mean number of high-quality embryos (P=0.011) was higher in the dual trigger group.

CONCLUSIONS

Dual trigger of oocyte maturation was not associated with any change in the live delivery rate but was associated with improvements in the quantity and quality of embryos; it could optimize pregnancy outcomes for normal ovarian responders.

Analytical characterization of recombinant hCG and comparative studies with reference product

INTRODUCTION

Regulatory agencies recommend a stepwise approach for demonstrating biosimilarity between a proposed biosimilar and reference biological product emphasizing for functional and structural characterization to trace if there is any difference which may impact safety and efficacy. We studied the comparative structural and biological attributes of recombinant human chorionic gonadotropin (rhCG), SB005, with reference product, Ovidrel® and Ovitrelle®. Recombiant hCG was approved in 2000 by the US Food and Drug Administration for the induction of final follicular maturation, early luteinization in infertile women as part of assisted reproductive technology program. It is also indicated for the induction of ovulation and pregnancy in ovulatory infertile patients whose cause of infertility is not due to ovarian failure.

MATERIALS AND METHODS

Primary structure was studied by intact mass analysis, peptide fingerprinting, peptide mass fingerprinting and sequence coverage analysis. Higher order structure was studied by circular dichroism, ultraviolet-visible spectroscopy, fluorescence spectroscopy, and disulfide bridge analysis. Different isoforms of reference product and SB005 were identified using capillary isoelectric focusing and capillary zone electrophoresis. Glycosylation was studied by N-glycan mapping using LC-ESI-MS, point of glycosylation, released glycan analysis using ultra performance liquid chromatography and sialic acid analysis. Product related impurities such as oligomer content analysis and oxidized impurities were studied using size exclusion chromatography and reverse phase high performance liquid chromatography, respectively. Biological activity in term of potency of reference product and SB005 was studied by in vivo analysis.

RESULTS AND CONCLUSION

In this study we have compared analytical similarity of recombinant rhCG (SB005) produced at Sun Pharmaceuticals with the reference product with respect to its primary, higher order structure, isoforms, charge variants, glycosylation, sialyation pattern, pharmacodynamic and in vivo efficacy. Our studies show that the in house produced rhCG has a high degree of structural and functional similarity with the reference product available in the market.

Association Between Progesterone Elevation on the Day of Human Chronic Gonadotropin Trigger and Pregnancy Outcomes After Fresh Embryo Transfer in In Vitro Fertilization/Intracytoplasmic Sperm Injection Cycles

Progesterone elevation (PE) during the late follicular phase of controlled ovarian stimulation in fresh embryo transfer in vitro fertilization (IVF)/intracytoplasmic sperm injection cycles has been claimed to be associated with decreased pregnancy rates. However, the evidence is not unequivocal, and clinicians still have questions about the clinical validity of measuring P levels during the follicular phase of stimulated cycles. We reviewed the existing literature aimed at answering four relevant clinical questions, namely (i) Is gonadotropin type associated with PE during the follicular phase of stimulated cycles? (ii) Is PE on the day of human chorionic gonadotropin (hCG) associated with negative fresh embryo transfer IVF/intracytoplasmic sperm injection (ICSI) cycles outcomes in all patient subgroups? (iii) Which P thresholds are best to identify patients at risk of implantation failure due to PE in a fresh embryo transfer? and (iv) Should a freeze all policy be adopted in all the cycles with PE on the day of hCG? The existing evidence indicates that late follicular phase progesterone rise in gonadotropin releasing analog cycles is mainly caused by the supraphysiological stimulation of granulosa cells with exogenous follicle-stimulating hormone. Yet, the type of gonadotropin used for stimulation seems to play no significant role on progesterone levels at the end of stimulation. Furthermore, PE is not a universal phenomenon with evidence indicating that its detrimental consequences on pregnancy outcomes do not affect all patient populations equally. Patients with high ovarian response to control ovarian stimulation are more prone to exhibit PE at the late follicular phase. However, in studies showing an overall detrimental effect of PE on pregnancy rates, the adverse effect of PE on endometrial receptivity seems to be offset, at least in part, by the availability of good quality embryo for transfer in women with a high ovarian response. Given the limitations of the currently available assays to measure progesterone at low ranges, caution should be applied to adopt specific cutoff values above which the effect of progesterone rise could be considered detrimental and to recommend "freeze-all" based solely on pre-defined cutoff points.

Retrospective analysis of treatments with recombinant FSH and recombinant LH versus human menopausal gonadotropin in women with reduced ovarian reserve

PURPOSES

The aim of this study is to determine whether a clinical advantage is gained with use of LH in combination with FSH or as a component of human menopausal gonadotropin (hMG) to achieve optimal ovarian stimulation.

METHODS

In this study, we compared retrospectively two regimens, r-FSH/r-LH and hMG, for the treatment of women with reduced ovarian reserve, identified as subjects with antral follicle count (AFC) < 11 and AMH ≤ 1.1 ng/ml.

RESULTS

Overall, the clinical pregnancy per started cycle was higher in the r-FSH/r-LH group (12.5 vs. 8.1%, P < 0.02), while implantation (11.1 vs. 9.5%) and miscarriage rates (29.9 vs. 35.9%) were comparable. Data were further analysed performing separate comparisons in subpopulations with different ranges of AFC, i.e. < 4, 4-6 and 7-10. Major differences between the two regimens were observed in women with AFC < 4. In this subpopulation, not only was the clinical pregnancies per started cycle higher in the r-FSH/r-LH group (10.2 vs. 1.5%, P < 0.01), but also implantation was significantly higher (13.0 vs. 2.8%, P < 0.02).

CONCLUSIONS

A r-FSH/r-LH regimen appears to be beneficial for the treatment of women with extremely poor ovarian reserve. It should be considered however that, being retrospective, this study is affected by obvious limitations, such as post-treatment patient selection criteria and absence of randomisation.

A second dose of kisspeptin-54 improves oocyte maturation in women at high risk of ovarian hyperstimulation syndrome: a Phase 2 randomized controlled trial

STUDY QUESTION

Can increasing the duration of LH-exposure with a second dose of kisspeptin-54 improve oocyte maturation in women at high risk of ovarian hyperstimulation syndrome (OHSS)?

SUMMARY ANSWER

A second dose of kisspeptin-54 at 10 h following the first improves oocyte yield in women at high risk of OHSS.

WHAT IS KNOWN ALREADY

Kisspeptin acts at the hypothalamus to stimulate the release of an endogenous pool of GnRH from the hypothalamus. We have previously reported that a single dose of kisspeptin-54 results in an LH-surge of ~12-14 h duration, which safely triggers oocyte maturation in women at high risk of OHSS.

STUDY DESIGN, SIZE, DURATION

Phase-2 randomized placebo-controlled trial of 62 women at high risk of OHSS recruited between August 2015 and May 2016. Following controlled ovarian stimulation, all patients (n = 62) received a subcutaneous injection of kisspeptin-54 (9.6 nmol/kg) 36 h prior to oocyte retrieval. Patients were randomized 1:1 to receive either a second dose of kisspeptin-54 (D; Double, n = 31), or saline (S; Single, n = 31) 10 h thereafter. Patients, embryologists, and IVF clinicians remained blinded to the dosing allocation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Study participants: Sixty-two women aged 18-34 years at high risk of OHSS (antral follicle count ≥23 or anti-Mullerian hormone level ≥40 pmol/L). Setting: Single centre study carried out at Hammersmith Hospital IVF unit, London, UK. Primary outcome: Proportion of patients achieving an oocyte yield (percentage of mature oocytes retrieved from follicles ≥14 mm on morning of first kisspeptin-54 trigger administration) of at least 60%. Secondary outcomes: Reproductive hormone levels, implantation rate and OHSS occurrence.

MAIN RESULTS AND THE ROLE OF CHANCE

A second dose of kisspeptin-54 at 10 h following the first induced further LH-secretion at 4 h after administration. A higher proportion of patients achieved an oocyte yield ≥60% following a second dose of kisspeptin-54 (Single: 14/31, 45%, Double: 21/31, 71%; absolute difference +26%, CI 2-50%, P = 0.042). Patients receiving two doses of kisspeptin-54 had a variable LH-response following the second kisspeptin dose, which appeared to be dependent on the LH-response following the first kisspeptin injection. Patients who had a lower LH-rise following the first dose of kisspeptin had a more substantial 'rescue' LH-response following the second dose of kisspeptin. The variable LH-response following the second dose of kisspeptin resulted in a greater proportion of patients achieving an oocyte yield ≥60%, but without also increasing the frequency of ovarian over-response and moderate OHSS (Single: 1/31, 3.2%, Double: 0/31, 0%).

LIMITATIONS, REASONS FOR CAUTION

Further studies are warranted to directly compare kisspeptin-54 to more established triggers of oocyte maturation.

WIDER IMPLICATIONS OF THE FINDINGS

Triggering final oocyte maturation with kisspeptin is a novel therapeutic option to enable the use of fresh embryo transfer even in the woman at high risk of OHSS.

STUDY FUNDING/COMPETING INTEREST(S)

The study was designed, conducted, analysed and reported entirely by the authors. The Medical Research Council (MRC), Wellcome Trust & National Institute of Health Research (NIHR) provided research funding to carry out the studies. There are no competing interests to declare.

TRIAL REGISTRATION NUMBER

Clinicaltrial.gov identifier NCT01667406.

TRIAL REGISTRATION DATE

8 August 2012.

DATE OF FIRST PATIENT'S ENROLMENT

10 August 2015.

The effect of human chorionic gonadotrophin contained in human menopausal gonadotropin on the clinical outcomes during progestin-primed ovarian stimulation

Progestin-primed ovarian stimulation (PPOS) protocol has recently been demonstrated to be an novel regimen for preventing premature LH surges during controlled ovarian hyperstimulation (COH) in combination with frozen-thawed embryo transfer (FET). Our prospective controlled study was to explore the effect of human chorionic gonadotropin (hCG) contained in human menopausal gonadotropin (hMG) on the clinical outcomes in normalovulatory women undergoing COH with PPOS. A total of 180 patients were allocated into three groups according to the gonadotropin (Gn) used: group A (human menopausal gonadotropin, hMG-A), group B (hMG-B) or group C (follicle stimulating hormone, FSH). The primary outcome measured was the number of oocytes retrieved. The number of oocytes retrieved in group A B C was 10.72±5.78 11.33±5.19and13.38±8.97, respectively, with no statistic significance (p>0.05). Other embryological indicators were also similar (p>0.05). The concentration of serum and urinary β-hCG on the trigger day in group A and B were not associated with embryo results (p>0.05). There was no significant differences in the clinical pregnancy rate (41.67% vs. 51.56% vs. 39.51%, p>0.05) and implantation rate (31.58%vs. 34.75%vs.25.33%) after FET among the three groups. Thus the clinical characteristics were not affected by the hCG contained in hMG in normalovulatory women treated with PPOS.

Influence of gonadotropins on ovarian follicle growth and developmentin vivoandin vitro

Gonadotropins are the key regulators of ovarian follicles development. They are applied in therapeutic practice in assisted reproductive technology clinics. In the present review we discuss the basic gonadotropic hormones – recombinant human follicle-stimulating hormone, its derivatives, luteinizing hormone and gonadotropin serum of pregnant mares, their origin, and application in ovarian follicle systems inin vitroculture systems.

A proteomic analysis identifies candidate early biomarkers to predict ovarian hyperstimulation syndrome in polycystic ovarian syndrome patients

Ovarian hyperstimulation syndrome (OHSS) is a potentially life‑threatening, iatrogenic complication that occurs during assisted reproduction. Polycystic ovarian syndrome (PCOS) significantly increases the risk of OHSS during controlled ovarian stimulation. Therefore, a more effective early prediction technique is required in PCOS patients. Quantitative proteomic analysis of serum proteins indicates the potential diagnostic value for disease. In the present study, the authors revealed the differentially expressed proteins in OHSS patients with PCOS as new diagnostic biomarkers. The promising proteins obtained from liquid chromatography‑mass spectrometry were subjected to ELISA and western blotting assay for further confirmation. A total of 57 proteins were identified with significant difference, of which 29 proteins were upregulated and 28 proteins were downregulated in OHSS patients. Haptoglobin, fibrinogen and lipoprotein lipase were selected as candidate biomarkers. Receiver operating characteristic curve analysis demonstrated all three proteins may have potential as biomarkers to discriminate OHSS in PCOS patients. Haptoglobin, fibrinogen and lipoprotein lipase have never been reported as a predictive marker of OHSS in PCOS patients, and their potential roles in OHSS occurrence deserve further studies. The proteomic results reported in the present study may gain deeper insights into the pathophysiology of OHSS.

Pharmacokinetic, pharmacodynamic, and clinical aspects of ovulation induction agents: A review of the literature

Controlled ovarian hyperstimulation is a key step for successful outcomes of assisted reproductive technique cycle outcomes. Many medications are available, which are commonly useed solely or in combination to achieve multiple follicular development. Pharmacokinetic, pharmacodynamic, and clinical information of ovulation induction drugs deserve to be elucidated for every individual patient before commencing infertility treatment. New concepts and new treatment protocols are introduced as ovulation physiology is understood by infertility specialists. Increasing treatment success by minimizing aderse effects is a milestone of all ovarian stimulation protocols that use these novel interventions. Achievement of a satisfactory cycle outcome includes retrieval of sufficient oocytes, a single clinical pregnancy, and avoidance of ovarian hyperstimulation syndrome. In this review, we evaluate the current literature to determine the most reliable and relevant information about the most used ovulation induction drugs.

Determination of biological activity of gonadotropins hCG and FSH by Förster resonance energy transfer based biosensors

Determination of biological activity of gonadotropin hormones is essential in reproductive medicine and pharmaceutical manufacturing of the hormonal preparations. The aim of the study was to adopt a G-protein coupled receptor (GPCR)-mediated signal transduction pathway based assay for quantification of biological activity of gonadotropins. We focussed on studying human chorionic gonadotropin (hCG) and follicle-stimulating hormone (FSH), as these hormones are widely used in clinical practice. Receptor-specific changes in cellular cyclic adenosine monophosphate (cAMP, second messenger in GPCR signalling) were monitored by a Förster resonance energy transfer (FRET) biosensor protein TEpacVV in living cells upon activation of the relevant gonadotropin receptor. The BacMam gene delivery system was used for biosensor protein expression in target cells. In the developed assay only biologically active hormones initiated GPCR-mediated cellular signalling. High assay sensitivities were achieved for detection of hCG (limit of detection, LOD: 5 pM) and FSH (LOD: 100 pM). Even the small-scale conformational changes caused by thermal inactivation and reducing the biological activity of the hormones were registered. In conclusion, the proposed assay is suitable for quantification of biological activity of gonadotropins and is a good alternative to antibody- and animal-testing-based assays used in pharmaceutical industry and clinical research.

Outcomes and Recommendations of an Indian Expert Panel for Improved Practice in Controlled Ovarian Stimulation for Assisted Reproductive Technology

Purpose. To improve success of in vitro fertilization (IVF), assisted reproductive technology (ART) experts addressed four questions. What is optimum oocytes number leading to highest live birth rate (LBR)? Are cohort size and embryo quality correlated? Does gonadotropin type affect oocyte yield? Should “freeze-all” policy be adopted in cycles with progesterone >1.5 ng/mL on day of human chorionic gonadotropin (hCG) administration? Methods. Electronic database search included ten studies on which panel gave opinions for improving current practice in controlled ovarian stimulation for ART. Results. Strong association existed between retrieved oocytes number (RON) and LBRs. RON impacted likelihood of ovarian hyperstimulation syndrome (OHSS). Embryo euploidy decreased with age, not with cohort size. Progesterone > 1.5 ng/dL did not impair cycle outcomes in patients with high cohorts and showed disparate results on day of hCG administration. Conclusions. Ovarian stimulation should be designed to retrieve 10–15 oocytes/treatment. Accurate dosage, gonadotropin type, should be selected as per prediction markers of ovarian response. Gonadotropin-releasing hormone (GnRH) antagonist based protocols are advised to avoid OHSS. Cumulative pregnancy rate was most relevant pregnancy endpoint in ART. Cycles with serum progesterone ≥1.5 ng/dL on day of hCG administration should not adopt “freeze-all” policy. Further research is needed due to lack of data availability on progesterone threshold or index.

Efficacy of Follicle-Stimulating Hormone (FSH) Alone, FSH + Luteinizing Hormone, Human Menopausal Gonadotropin or FSH + Human Chorionic Gonadotropin on Assisted Reproductive Technology Outcomes in the "Personalized" Medicine Era: A Meta-analysis

SETTING

Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) act on the same receptor, activating different signal transduction pathways. The role of LH or hCG addition to follicle-stimulating hormone (FSH) as well as menopausal gonadotropins (human menopausal gonadotropin; hMG) in controlled ovarian stimulation (COS) is debated.

OBJECTIVE

To compare FSH + LH, or FSH + hCG or hMG vs. FSH alone on COS outcomes.

DESIGN

A meta-analysis according to PRISMA statement and Cochrane Collaboration was performed, including prospective, controlled clinical trials published until July 2016, enrolling women treated with FSH alone or combined with other gonadotropins. Trials enrolling women with polycystic ovarian syndrome were excluded (PROSPERO registration no. CRD42016048404).

RESULTS

Considering 70 studies, the administration of FSH alone resulted in higher number of oocytes retrieved than FSH + LH or hMG. The MII oocytes number did not change when FSH alone was compared to FSH + LH, FSH + hCG, or hMG. Embryo number and implantation rate were higher when hMG was used instead of FSH alone. Pregnancy rate was significantly higher in FSH + LH-treated group vs. others. Only 12 studies reported live birth rate, not providing protocol-dependent differences. Patients' stratification by GnRH agonist/antagonist identified patient subgroups benefiting from specific drug combinations.

CONCLUSION

In COS, FSH alone results in higher oocyte number. HMG improves the collection of mature oocytes, embryos, and increases implantation rate. On the other hand, LH addition leads to higher pregnancy rate. This study supports the concept of a different clinical action of gonadotropins in COS, reflecting previous in vitro data.

Modulation of Human Sperm Capacitation by Progesterone, Estradiol, and Luteinizing Hormone

Sperm residency in female reproductive tract is essential to undergo functional changes that allow the cell to encounter the oocyte and fertilize it. Those changes, known as capacitation, are modulated by molecules located in the uterotubal surface and fluids. During the fertile window, there is a notable increase in some reproductive hormones such as progesterone, estradiol, and luteinizing hormone in the female reproductive tract, so spermatozoa are exposed to these hormones in an environment that must favor gamete encountering and fusion. This spatiotemporal coincidence suggests that they are suitable candidates to modulate sperm function in order to synchronize the events that ultimately allow the success of fertilization. The presence of receptors for these hormones in the human sperm has been described, but their physiological relevance and mechanisms of action have been either subject of controversy or not properly investigated. This review intends to summarize the evidence that support the participation of these hormones in the regulation of sperm capacitation.

Mouse Models for the Study of Synthesis, Secretion, and Action of Pituitary Gonadotropins

Gonadotropins play fundamental roles in reproduction. More than 30years ago, Cga transgenic mice were generated, and more than 20years ago, the phenotypes of Cga null mice were reported. Since then, numerous mouse strains have been generated and characterized to address several questions in reproductive biology involving gonadotropin synthesis, secretion, and action. More recently, extragonadal expression, and in some cases, functions of gonadotropins in nongonadal tissues have been identified. Several genomic and proteomic approaches including novel mouse genome editing tools are available now. It is anticipated that these and other emerging technologies will be useful to build an integrated network of gonadotropin signaling pathways in various tissues. Undoubtedly, research on gonadotropins will continue to provide new knowledge and allow us transcend from benchside to the bedside.

Structural and functional biology of arachidonic acid 15-lipoxygenase-1 (ALOX15)

Lipoxygenases (LOX) form a family of lipid peroxidizing enzymes, which have been implicated in a number of physiological processes and in the pathogenesis of inflammatory, hyperproliferative and neurodegenerative diseases. They occur in two of the three domains of terrestrial life (bacteria, eucarya) and the human genome involves six functional LOX genes, which encode for six different LOX isoforms. One of these isoforms is ALOX15, which has first been described in rabbits in 1974 as enzyme capable of oxidizing membrane phospholipids during the maturational breakdown of mitochondria in immature red blood cells. During the following decades ALOX15 has extensively been characterized and its biological functions have been studied in a number of cellular in vitro systems as well as in various whole animal disease models. This review is aimed at summarizing the current knowledge on the protein-chemical, molecular biological and enzymatic properties of ALOX15 in various species (human, mouse, rabbit, rat) as well as its implication in cellular physiology and in the pathogenesis of various diseases.