Inhibin-B secretion and FSH isoform distribution may play an integral part of follicular selection in the natural menstrual cycle

Cascaded autocatalytic hairpin assembly molecular circuit for amplified fluorescent aptamer luteinising hormone assay

The quantitative detection of luteinising hormone (LH) is critical for the study of the physiological mechanism of reproductive function and the assessment of infertility and the clinical treatment of reproductive disorders. However, conventional approaches for LH detection are mostly based on an antibody recognition module with the limitations of sensitivity, simplicity and cost. The development of robust LH sensing methods is therefore highly demanded for facilitating the diagnosis of LH-related diseases. We establish a convenient, amplified and sensitive fluorescent aptamer LH assay based on new target-triggered and cascaded autocatalytic hairpin assembly (C-aCHA) circuit amplification means via initiator sequence replication. Target LH molecules bind the aptamers in the aptamer/initiator duplexes to release the initiator sequences, which trigger CHA formation of DNA three-way junctions (TWJs) and the unfolding of fluorescently quenched signal hairpins to show amplified fluorescence. The TWJs further activate another CHA cycle for the yield of more initiator sequences to form the C-aCHA circuit amplification cycles, which lead to the unfolding of many signal hairpins to exhibit substantially magnified fluorescence recovery for detecting LH down to 8.56 pM in the range from 10 pM to 50 nM. In addition, the monitoring of trace LH in diluted serums by this sensing approach has been also verified. Our LH assay clearly outperforms current existing antibody-based methods and the C-aCHA signal amplification strategy can be easily extended as a robust means for sensitively monitoring various biomolecular markers with simple replacement of the corresponding aptamers for diverse applications.

Relationship between semen parameters, serum InhB, and INSL-3 levels, and the degree of varicocele

BACKGROUND

Varicocele is an abnormal expansion of the pampininias venous plexus in the scrotum, resulting in impaired sperm production and reduced sperm quality. The exact pathophysiological mechanism leading to varicocele-related infertility has not been fully elucidated. Although treatable, varicocele may lead to male infertility.

OBJECTIVE

To investigate the relationship between semen parameters, serum InhB and INSL-3 levels, and the degree of varicocele in male patients.

METHODS

Serum InhB and INSL-3 were detected. To evaluate the relationship between semen parameters and serum InhB and INSL-3 levels. To evaluate the value of semen parameters and serum InhB and INSL-3 levels in distinguishing disease severity in patients with varicocele.

RESULTS

Serum INSL-3 in patients with varicocele decreased with the severity of the disease. Serum INSL-3 was positively correlated with total sperm count and frequency of normal sperm morphology. There was a weak correlation between serum InhB and semen volume, concentration, and total sperm. Patients with different disease severity were similar within the groups, with partial overlap or similarity between varicocele Grade I and Grade II, and significant differences between Grade III and Grade I and II. Semen volume, concentration, total sperm, normal sperm morphology, and serum InhB and INSL-3 levels could distinguish the degree of varicocele.

CONCLUSION

Semen parameters and the combination of serum InhB and INSL-3 levels in patients with varicocele are closely related to the severity of the disease. Serum INSL-3 is expected to be a potential biomarker for early clinical intervention.

The Oxidative Phosphorylation and Cytoskeleton Proteins of Mouse Ovaries after 96 Hours of Hindlimb Suspension

The purpose of this study was to assess oxidative phosphorylation (OXPHOS) in mouse ovaries, determine the relative content of proteins that form the respiratory chain complexes and the main structures of the cytoskeleton, and determine the mRNA of the corresponding genes after hindlimb suspension for 96 h. After hindlimb suspension, the maximum rate of oxygen uptake increased by 133% (p < 0.05) compared to the control due to the complex I of the respiratory chain. The content of mRNA of genes encoding the main components of the respiratory chain increased (cyt c by 78%, cox IV by 56%, ATPase by 69%, p < 0.05 compared with the control). The relative content of cytoskeletal proteins that can participate in the processes of transport and localization of mitochondria does not change, with the exception of an increase in the content of alpha-tubulin by 25% (p < 0.05) and its acetylated isoform (by 36%, p < 0.05); however, the mRNA content of these cytoskeletal genes did not differ from the control. The content of GDF9 mRNA does not change after hindlimb suspension. The data obtained show that short-term exposure to simulated weightlessness leads to intensification of metabolism in the ovaries.

Impact of 2.5 mg versus 5 mg letrozole co-treatment in an antagonist protocol for IVF: a retrospective study

Objective

The present study aimed to compare the effectiveness of two different doses of letrozole (2.5 mg and 5 mg daily) in an antagonist protocol for infertile women with normal ovarian reserve.

Methods

This retrospective cohort study included infertile women who underwent in vitro fertilization treatment with letrozole co-treatment at doses of 2.5 mg and 5 mg from 2007 - 2021 at Shanghai Ninth People's Hospital (Shanghai, China). The control group comprised infertile women who received gonadotropin-releasing hormone antagonist alone. The primary outcome was the cumulative live birth rate, while secondary outcomes included follicular phase endocrine parameters, ovarian stimulation outcomes, pregnancy outcomes, and the incidences of maternal and neonatal complications. Baseline and follow-up data were compared between the groups using ANOVA for normally distributed variables, the Kruskal-Wallis test for non-normally distributed variables, and the Chi-square test for categorical variables.

Results

A total of 422 participants were enrolled in the study, with 211 women in the antagonist group, 109 women in the 2.5 mg letrozole co-treatment group, and 102 women in the 5 mg letrozole co-treatment group. Letrozole co-treatment significantly suppressed oestradiol and follicle-stimulating hormone concentrations from stimulation day 5 and onwards, while increasing luteinizing hormone levels on stimulation day 5 and trigger day. The effect was more pronounced with a 5 mg dose of letrozole compared to a 2.5 mg dose (P < 0.05). Administration of 5 mg letrozole reduced the gonadotropin dose (P < 0.05) without negatively affecting the number of oocytes retrieved and subsequent embryo parameters (P > 0.05). The analysis of cumulative live birth rates showed rates of 29.4% in the letrozole 5 mg group, 27.5% in the letrozole 2.5 mg group, and 33.6% in the control group, with no statistically significant difference (P > 0.05). There were no reported pregnancy complications in the two letrozole groups. Additionally, there were no significant differences among the three groups in terms of gestational age and birth weight for both singleton and twin births.

Conclusion

This study indicates that the administration of letrozole in an antagonist protocol, at both 2.5 mg and 5 mg dosages, results in comparable clinical outcomes.

FSHR-mTOR-HIF1 signaling alleviates mouse follicles from AMPK-induced atresia

The majority of activated ovarian follicles undergo atresia during reproductive life in mammals, and only a small number of follicles are ovulated. Though hormone treatment has been widely used to promote folliculogenesis, the molecular mechanism behind follicle selection and atresia remains under debate due to inconsistency among investigation models. Using a high-throughput molecular pathology strategy, we depicted a transcriptional atlas of mouse follicular granulosa cells (GCs) under physiological condition and obtained molecular signatures in healthy and atresia GCs during development. Functional results revealed hypoxia-inducible factor 1 (HIF1) as a major effector downstream of follicle-stimulating hormone (FSH), and HIF1 activation is essential for follicle growth. Energy shortage leads to prevalent AMP-activated protein kinase (AMPK) activation and drives follicular atresia. FSHR-mTOR-HIF1 signaling helps follicles escape from the atresia fate, while energy stress persists. Our work provides a comprehensive understanding of the molecular network behind follicle selection and atresia under physiological condition.

Potential factors result in diminished ovarian reserve: a comprehensive review

The ovarian reserve is defined as the quantity of oocytes stored in the ovary or the number of oocytes that can be recruited. Ovarian reserve can be affected by many factors, including hormones, metabolites, initial ovarian reserve, environmental problems, diseases, and medications, among others. With the trend of postponing of pregnancy in modern society, diminished ovarian reserve (DOR) has become one of the most common challenges in current clinical reproductive medicine. Attributed to its unclear mechanism and complex clinical features, it is difficult for physicians to administer targeted treatment. This review focuses on the factors associated with ovarian reserve and discusses the potential influences and pathogenic factors that may explain the possible mechanisms of DOR, which can be improved or built upon by subsequent researchers to verify, replicate, and establish further study findings, as well as for scientists to find new treatments.

Protective effect of L‑carnitine against oxidative stress injury in human ovarian granulosa cells

Granulosa cells (GCs) are important for supporting and nourishing oocytes during follicular development and maturation. Oxidative stress (OS) injury of GCs can lead to decreased responsiveness of follicles to follicular stimulating hormone (FSH), which will accelerate ovarian senescence and adversely affect oocyte and embryo quality. Since L-carnitine has been previously reported to exert strong antioxidant activity, the present study aimed to explore the possible effects of L-carnitine on OS injury and FSH receptor (FSHR) expression in ovarian GCs, results of which may be of significance for GCs protection. In the present study, OS was induced in vitro in KGN cells by treatment with H₂O₂. KGN cells were cultured and divided into the following four groups: Blank, OS, and 40 and 80 µmol/l L-carnitine pre-treatment groups. In the OS group, cells showed nuclear pyknosis, mitochondria swelled irregularly whilst featuring fractured cristae. In addition, cell viability, ROS levels, superoxide dismutase levels, glutathione levels, malondialdehyde levels, the mitochondrial membrane potential and FSHR expression, as determined by Cell Counting Kit-8 (CCK-8), 2,7-dichloro-dihydrofluorescein diacetate, spectrophotometry, ELISA, spectrophotometry, JC-1 and western blot analyses, respectively, were all significantly different in the OS group compared with those in the control group. However, malonaldehyde levels, reactive oxygen species levels and the apoptosis rate according to flow cytometry were all significantly increased compared with those in the control. Compared with those in the OS group, the morphology of cells and mitochondria in the L-carnitine pre-treatment groups were improved, whilst cell viability and the expression of FSHR were significantly increased but oxidative stress injury was decreased. The present results suggest that L-carnitine can protect the cells from OS damage induced by H₂O₂, enhance antioxidant activity whilst suppressing the apoptosis of GCs, in addition to preserving FSHR expression in GCs under OS. Therefore, the present study revealed that the introduction of L-carnitine in clinical medicine or dietary supplement may protect GCs, improve follicular quality and female reproductive function.

Association between insulin resistance and abnormal menstrual cycle in Chinese patients with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder, which is characterized by insulin resistance (IR) and menstrual cycle disorders. IR is thought of as a pivotal cause of PCOS and related comorbidities. However, the link between IR and abnormal menstrual cycles in PCOS should be further studied. In this study, we clarified the dose-response relationship between IR and abnormal menstrual cycles in patients with PCOS.

RESULTS

In this retrospective study including 140 patients with PCOS, we found that there was a dose-response relationship between the increased HOMA-IR index and the level of menstrual cycle disorders (1.61 [95%CI: 1.37-1.85] for normal menstruation, 2.02 [95%CI: 1.61-2.44] for oligomenorrhea, 2.35 [95%CI:1.96-2.75] for amenorrhea, P for trend = 0.003). Further stratification analyses showed that this dose-response relationship was more evident in the patients who were younger, had higher BMI, higher AFC numbers, elevated levels of testosterone, anti-Müllerian hormone, inhibin B, and prolactin levels, and had a lower progestogen level.

CONCLUSIONS

Our study has established an association between IR and abnormal menstrual cycles in patients with PCOS, which can be affected by age, BMI, and hormone levels. Our results might be helpful for further prevention and treatment of amenorrhea in PCOS.

The State of the Organs of the Female Reproductive System after a 5-Day "Dry" Immersion

The impact of weightlessness on the female reproductive system remains poorly understood, although deep space exploration is impossible without the development of effective measures to protect women's health. The purpose of this work was to study the effect of a 5-day "dry" immersion on the state of the reproductive system of female subjects. On the fourth day of the menstrual cycle after immersion, we observed an increase in inhibin B of 35% (p < 0.05) and a decrease in luteinizing hormone of 12% (p < 0.05) and progesterone of 52% (p < 0.05) compared with the same day before immersion. The size of the uterus and the thickness of the endometrium did not change. On the ninth day of the menstrual cycle after immersion, the average diameters of the antral follicles and the dominant follicle were, respectively, 14% and 22% (p < 0.05) higher than before. The duration of the menstrual cycle did not change. The obtained results may indicate that the stay in the 5-day "dry" immersion, on the one hand, can stimulate the growth of the dominant follicle, but, on the other hand, can cause functional insufficiency of the corpus lutea.

Regulation of human oocyte maturation in vivo during the final maturation of follicles

STUDY QUESTION

Which substances and signal transduction pathways are potentially active downstream to the effect of FSH and LH in the regulation of human oocyte maturation in vivo?

SUMMARY ANSWER

The regulation of human oocyte maturation appears to be a multifactorial process in which several different signal transduction pathways are active.

WHAT IS KNOWN ALREADY

Many studies in animal species have provided insight into the mechanisms that govern the final maturation of oocytes. Currently, these studies have identified several different mechanisms downstream to the effects of FSH and LH. Some of the identified mechanisms include the regulation of cAMP/cGMP levels in oocytes involving C-type natriuretic peptide (CNP), effects of epidermal growth factor (EGF)-related peptides such as amphiregulin (AREG) and/or epiregulin (EREG), effect of TGF-β family members including growth differentiation factor 9 (GDF9) and morphogenetic protein 15 (BMP15), activins/inhibins, follicular fluid meiosis activating sterol (FF-MAS), the growth factor midkine (MDK), and several others. However, to what extent these pathways and mechanisms are active in humans in vivo is unknown.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 50 women undergoing fertility treatment in a standard antagonist protocol at a university hospital affiliated fertility clinic in 2016-2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We evaluated the substances and signalling pathways potentially affecting human oocyte maturation in follicular fluid (FF) and granulosa cells (GCs) collected at five time points during the final maturation of follicles. Using ELISA measurement and proteomic profiling of FF and whole genome gene expression in GC, the following substances and their signal transduction pathways were collectively evaluated: CNP, the EGF family, inhibin-A, inhibin-B, activins, FF-MAS, MDK, GDF9, and BMP15.

MAIN RESULTS AND THE ROLE OF CHANCE

All the evaluated substances and signal transduction pathways are potentially active in the regulation of human oocyte maturation in vivo except for GDF9/BMP15 signalling. In particular, AREG, inhibins, and MDK were significantly upregulated during the first 12-17 h after initiating the final maturation of follicles and were measured at significantly higher concentrations than previously reported. Additionally, the genes regulating FF-MAS synthesis and metabolism were significantly controlled in favour of accumulation during the first 12-17 h. In contrast, concentrations of CNP were low and did not change during the process of final maturation of follicles, and concentrations of GDF9 and BMP15 were much lower than reported in small antral follicles, suggesting a less pronounced influence from these substances.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

Although GC and cumulus cells have many similar features, it is a limitation of the current study that information for the corresponding cumulus cells is not available. However, we seldom recovered a cumulus-oocyte complex during the follicle aspiration from 0 to 32 h.

WIDER IMPLICATIONS OF THE FINDINGS

Delineating the mechanisms governing the regulation of human oocyte maturation in vivo advances the possibility of developing a platform for IVM that, as for most other mammalian species, results in healthy offspring with good efficacy. Mimicking the intrafollicular conditions during oocyte maturation in vivo in small culture droplets during IVM may enhance oocyte nuclear and cytoplasmic maturation. The primary outlook for such a method is, in the context of fertility preservation, to augment the chances of achieving biological children after a cancer treatment by subjecting oocytes from small antral follicles to IVM. Provided that aspiration of oocytes from small antral follicles in vivo can be developed with good efficacy, IVM may be applied to infertile patients on a larger scale and can provide a cheap alternative to conventional IVF treatment with ovarian stimulation. Successful IVM has the potential to change current established techniques for infertility treatment.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the University Hospital of Copenhagen, Rigshospitalet, the Independent Research Fund Denmark (grant number 0134-00448), and the Interregional EU-sponsored ReproUnion network. There are no conflicts of interest to be declared.

miR-450-5p and miR-202-5p Synergistically Regulate Follicle Development in Black Goat

Follicle maturation is a complex biological process governed by numerous factors, and researchers have observed follicle development by studying the proliferation and apoptosis of follicular granulosa cells (GCs). However, the regulatory mechanisms of GCs proliferation and death during follicle development are largely unknown. To investigate the regulatory mechanisms of lncRNAs, mRNAs, and microRNAs, RNA sequencing (RNA-seq) and small RNA-seq were performed on large (>10 mm) and small follicles (<3 mm) of Leizhou black goat during estrus. We discovered two microRNAs, miR-450-5p and miR-202-5p, which can target GCs in goats and may be involved in follicle maturation, and the effects of miR-450-5p and miR-202-5p on ovarian granulosa cell lines were investigated (KGN). Using cell counting kit-8 (CCK-8) assays, 5-Ethynyl-2’-deoxyuridine (EdU) assay and flow cytometry, miR-202-5p overexpression could suppress the proliferation and induce apoptosis of GCs, whereas miR-450-5p overexpression induced the opposite effects. The dual-luciferase reporter assay confirmed that miR-450-5p could directly target the BMF gene (a BCL2 modifying factor), and miR-202-5p targeted the BCL2 gene. A considerable rise in phosphorylated Akt (p-AKT) protein was observed following the downregulation of BMF by miR-450-5p mimics. After BMF gene RNAi therapy, a notable elevation in p-AKT was detected. Mimics of miR-202-5p inhibited BCL2 protein expression, significantly decreasing p-AMPK protein expression. These results imply that during the follicular development in black goats, the miR-450-5p-BMF axis favored GC proliferation on a wide scale, while the miR-202-5p-BCL2 axis triggered GC apoptosis.

Effects of follicle-stimulating hormone on fat metabolism and cognitive impairment in women during menopause

Lipid metabolism disorder is a common pathological manifestation of menopausal women, and is also an important risk factor for many diseases at this stage of life. Epidemiological studies have shown that high levels of follicle-stimulating hormone (FSH) in menopausal women are closely associated with changes in body composition, central obesity, and cognitive decline. Exogenous FSH causes growth and proliferation of adipose, whereas blockage of the FSH signaling pathway leads to decline in adipose. Mechanistically, FSH, FSH receptor (FSHR), G protein coupling, gene mutation and other pathways are involved in adipogenesis and cognitive impairment. Here, we review the critical role and potential interactions of FSH in adipogenesis and cognitive impairment in menopausal women. Further understanding of the exact mechanisms of FSH aggravating obesity and cognitive impairment may provide a new perspective for promoting healthy aging in menopausal women.

Effects of letrozole cotreatment on endocrinology and follicle development in women undergoing ovarian stimulation in an antagonist protocol

STUDY QUESTION

What are the downstream endocrine and paracrine consequences of letrozole (LZ) cotreatment during ovarian stimulation and is follicle growth and recruitment affected?

SUMMARY ANSWER

Letrozole cotreatment induces marked changes in both the follicular and luteal phase endocrinology causing potentiation of follicle diameter and an improved corpus luteum function without affecting the secondarily recruited follicle cohort.

WHAT IS KNOWN ALREADY

Letrozole is a third-generation aromatase inhibitor that is well-established as an effective ovulatory agent, while its possible benefits in standard in vitro fertilization protocols are less thoroughly investigated.

STUDY DESIGN, SIZE, DURATION

This study included a double-blinded, placebo-controlled, randomized study with LZ or placebo intervention during ovarian stimulation for IVF treatment, an observational preceding baseline natural cycle and a succeeding follow-up visit. Participants were enrolled between August 2016 and November 2018. Data from the randomized, stimulated cycle were part of a larger RCT, which was previously published.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was conducted at a public fertility clinic at Herlev Hospital, Denmark, including 31 healthy, normo-responding women eligible for IVF treatment. They underwent a natural baseline cycle and were subsequently randomized to receive either LZ 5 mg (n = 16) or placebo (n = 15) daily during ovarian stimulation from cycle day (CD) 2-3 until induction of ovulation. Throughout both cycles, monitoring was performed every third day with transvaginal ultrasound for assessment of follicle count and diameter, and blood analyses for the determination of twelve endocrine and paracrine parameters. A follow-up assessment was performed at CD2-3 in the succeeding cycle. In the randomized part of the study, we determined differences in blood parameters, follicle recruitment, and follicle diameter. In the observational part of the study, we assessed follicle recruitment in between cycles and its correlation to endocrine parameters.

MAIN RESULTS AND THE ROLE OF CHANCE

Letrozole cotreatment significantly suppressed oestradiol (E2) concentrations in the follicular phase (area under the curve (AUC) -58% (95% CI [-70%; -43%], P < 0.001)) and luteal phase (AUC -39% [-63%; -1%], P = 0.046). This had a marked effect on the endocrine and paracrine output with increased follicular phase luteinizing hormone (AUC +37% [3%; 82%], P = 0.033), androstenedione (AUC +36% [6%; 74%], P = 0.016), testosterone (AUC +37% [7%; 73%], P = 0.013) and 17-OH-progesterone (AUC +114% [10%; 318%], P = 0.027). Furthermore, follicle-stimulating hormone (FSH) was increased at stimulation day 5 in the LZ group (P < 0.05). In the luteal phase, increased corpus luteum output was reflected by elevated progesterone (AUC +44% [1%; 104%], P = 0.043), inhibin A (AUC +52% [11%; 108%], P = 0.011), androstenedione (AUC +31% [9%; 58%], P = 0.006) and testosterone (AUC +29% [6%; 57%], P = 0.012) in the LZ group. The altered balance between oestrogens and androgens was reflected in a markedly reduced SHBG concentration in the LZ group throughout the luteal phase (AUC -35% [-52%; -11%], P = 0.009). Endocrine and paracrine parameters were similar between groups at the follow-up visit. Letrozole cotreatment significantly increased the mean number of follicles >16 mm at oocyte retrieval (7.2 vs 5.2, difference: 2.0, 95% CI [0.1; 3.8], P = 0.036), while the mean total number of follicles at oocyte retrieval was the same (23.7 vs 23.5, difference: 0.2 [-5.8; 6.1], P = 0.958), and the mean FSH consumption during the stimulated cycle was similar (1500 vs 1520 IU, difference -20 IU [-175; 136], P = 0.794). Between cycles, the mean antral follicle count at CD2-3 was unchanged (natural cycle 19.0, stimulated cycle 20.9, follow-up cycle 19.7, P = 0.692) and there was no effect of LZ cotreatment on the recruitment of the next follicle cohort (test for interaction, P = 0.821).

LIMITATIONS, REASONS FOR CAUTION

This study included a relatively small, selected group of healthy women with an expected normal ovarian function and reserve, and the effects of LZ may therefore be different in other patient groups.

WIDER IMPLICATIONS OF THE FINDINGS

We confirm some previous findings concerning increased follicle growth and increased endogenous FSH and androgen production, which support the rationale for further studies on the use of LZ cotreatment, for example, as a form of endogenous androgen priming sensitizing the follicle to FSH. Letrozole appears to improve the luteal phase with better stimulation of corpus luteum and progesterone secretion.

STUDY FUNDING/COMPETING INTEREST(S)

The authors declare no conflicts of interest relating to the present work.

TRIAL REGISTRATION NUMBER

NCT02939898.

Evaluation of Serum AMH, INHB Combined with Basic FSH on Ovarian Reserve Function after Laparoscopic Ovarian Endometriosis Cystectomy

Objective

The value of serum AMH, INHB, and bFSH levels in assessing postoperative ovarian reserve function was analyzed by measuring serum anti-Mullerian hormone (AMH), inhibin B (INHB), and basal follicle-stimulating hormone (bFSH) levels in patients after laparoscopic cystectomy for endometrioma.

Methods

From June 2019 to December 2021, 124 patients underwent laparoscopic cystectomy for endometrioma in our hospital were selected, and the serum AMH, INHB, bFSH level, antral follicle count (AFC) of all patients before and after operation were detected and compared. According to the results of postoperative testing, all the patients were divided into normal group (n = 86), diminished ovarian reserve (DOR) group (n = 27), and premature ovarian failure (POF) group (n = 11). Pearson correlation model and subject operating characteristic curve (ROC) were used to analyze the correlation and diagnostic value of serum AMH, INHB and bFSH levels with postoperative ovarian reserve function, respectively.

Results

After operation, the levels of serum AMH, INHB and AFC in the DOR group and POF group decreased compared with those before the operation, and the serum bFSH levels increased (p < 0.05). After operation, the levels of serum AMH, INHB and AFC in DOR group and POF group were lower than those in normal group,and the serum bFSH levels were higher than the normal group; the levels of serum AMH, INHB and AFC in POF group were lower than those in DOR group, and the serum bFSH levels were higher than the DOR group (p < 0.05). Pearson analysis showed that serum AMH and INHB levels were negatively correlated with bFSH, and positively correlated with the number of AFC, the serum bFSH level was negatively correlated with the number of AFC (p < 0.05). The diagnostic values of serum AMH, bFSH, INHB and the combination of the three tests for postoperative abnormal ovarian reserve function were 0.866 (95% CI, 0.801–0.923), 0.810 (95% CI, 0.730–0.890), 0.774 (95% CI, 0.687–0.860) and 0.940 (95% CI, 0.900–0.981), respectively.

Conclusion

Serum AMH and INHB levels decreased and bFSH levels increased in patients after laparoscopic cystectomy for endometrioma, both of which were closely related to postoperative ovarian reserve function, and both could evaluate ovarian reserve function after ovarian cyst debulking, and the combined test could significantly improve the detection rate.

The Association Between Serum Estradiol Levels on hCG Trigger Day and Live Birth Rates in Non-PCOS Patients: A Retrospective Cohort Study

OBJECTIVE

To retrospectively analyze the association of serum estradiol (E2) levels on human chorionic gonadotropin (hCG) trigger day and live birth rates (LBRs) in women undergoing fresh embryo transfer and not exhibiting polycystic ovary syndrome.

DESIGN

Retrospective cohort study.

METHODS

Analysis of 13,950 patients who had fresh embryo transfer between December 2013 and December 2019. The main outcome measurement was LBRs. Multivariable regression analysis was performed to investigate associations between E2 levels on the hCG trigger day and LBRs. Stratification analysis was performed to test for effect modification in subgroups. Furthermore, a two-piecewise linear regression model was established to find nonlinear relationships.

RESULTS

Multivariable regression analysis showed a significant association between serum E2 levels on the hCG trigger day and LBRs, adjusting for covariates [relative risk (RR) 1.027, 95% confidence interval (CI) 1.007, 1.049]. Stratification analysis showed that the LBRs were positively associated (RR 1.052, 95% CI 1.004, 1.102) with every 1 ng/ml increase of serum E2 on the hCG trigger day for the subgroup with low antral follicle counts on the trigger day. Specifically, a two-piecewise linear regression model showed that there was a positive association (RR 1.188, 95% CI 1.057, 1.334) between serum E2 and LBR for every increase of 1 ng/ml E2 when the concentration of serum E2 was lower than 2.1 ng/ml. However, there was no significant association (RR 1.002, 95% CI 0.971, 1.032) between E2 levels and LBRs when the concentration of E2 was higher than the 2.1ng/ml inflection point.

CONCLUSIONS

Serum E2 levels on the hCG trigger day were segmentally connected with LBRs.

An Online Tool Using Basal or Activated Ovarian Reserve Markers to Predict the Number of Oocytes Retrieved Following Controlled Ovarian Stimulation: A Prospective Observational Cohort Study

BACKGROUND

Predicting the number of oocytes retrieved (NOR) following controlled ovarian stimulation (COS) is the only way to ensure effective and safe treatment in assisted reproductive technology (ART). To date, there have been limited studies about predicting specific NOR, which hinders the development of individualized treatment in ART.

OBJECTIVE

To establish an online tool for predicting NOR.

MATERIALS AND METHODS

In total, 621 prospective routine gonadotropin releasing hormone (GnRH) antagonist COS cycles were studied. Independent variables included age, body mass index, antral follicle counts, basal FSH, basal and increment of anti-mullerian hormone, Luteinizing hormon, estradiol, testosterone, androstenedione, and inhibin B. The outcome variable was NOR. The independent variables underwent appropriate transformation to achieve a better fit for a linear relationship with NOR. Pruned forward selection with holdback validation was then used to establish predictive models. Corrected Akaike's information criterion, Schwarz-Bayesian information criterion, scaled -log[likelihood], and the generalized coefficient of determination (R²) were used for model evaluation.

RESULTS

A multiple negative binomial regression model was used for predicting NOR because it fitted a negative binomial distribution. We established Model 1, using basal ovarian reserve markers, and Model 2, using both basal and early dynamic markers for predicting NOR following COS. The generalized R² values were 0.54 and 0.51 for Model 1 and 0.64 and 0.62 for Model 2 in the training and validation sets, respectively.

CONCLUSION

Models 1 and 2 could be applied to different scenarios. For directing the starting dose of recombinant follicle stimulation hormone (rFSH), Model 1 using basic predictors could be used prior to COS. Model 2 could be used for directing the adjustment of rFSH dosages during COS. An online tool (http://121.43.113.123:8002/) based on these two models is also developed. We anticipate that the clinical application of this tool could help the ART clinics to reduce iatrogenic ovarian under- or over-responses, and could reduce costs during COS for ART.

Impact of letrozole co-treatment during ovarian stimulation with gonadotrophins for IVF: a multicentre, randomized, double-blinded placebo-controlled trial

STUDY QUESTION

Does letrozole co-treatment during ovarian stimulation with gonadotrophins for IVF reduce the proportion of women with premature progesterone levels above 1.5 ng/ml at the time of triggering final oocyte maturation?

SUMMARY ANSWER

The proportion of women with premature progesterone above 1.5 ng/ml was not significantly affected by letrozole co-treatment.

WHAT IS KNOWN ALREADY

IVF creates multiple follicles with supraphysiological levels of sex steroids interrupting the endocrine milieu and affects the window of implantation. Letrozole is an effective aromatase inhibitor, normalizing serum oestradiol, thereby ameliorating some of the detrimental effects of IVF treatment.

STUDY DESIGN, SIZE, DURATION

A randomized, double-blinded placebo-controlled trial investigated letrozole intervention during stimulation for IVF with FSH. The trial was conducted at four fertility clinics at University Hospitals in Denmark from August 2016 to November 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A cohort of 129 women with expected normal ovarian reserve (anti-Müllerian hormone 8-32 nmol/l) completed an IVF cycle with fresh embryo transfer and received co-treatment with either 5 mg/day letrozole (n = 67) or placebo (n = 62), along with the FSH. Progesterone, oestradiol, FSH, LH and androgens were analysed in repeated serum samples collected from the start of the stimulation to the mid-luteal phase. In addition, the effect of letrozole on reproductive outcomes, total FSH consumption and adverse events were assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of women with premature progesterone >1.5 ng/ml was similar (6% vs 0% (OR 0.0, 95% CI [0.0; 1.6], P = 0.12) in the letrozole versus placebo groups, respectively), whereas the proportion of women with mid-luteal progesterone >30 ng/ml was significantly increased in the letrozole group: (59% vs 31% (OR 3.3, 95% CI [1.4; 7.1], P = 0.005)). Letrozole versus placebo decreased oestradiol levels on the ovulation trigger day by 68% (95% CI [60%; 75%], P < 0.0001). Other hormonal profiles, measured as AUC, showed the following results. The increase in LH in the letrozole group versus placebo group was 38% (95% CI [21%; 58%], P < 0.0001) and 34% (95% CI [11%; 61%], P = 0.006) in the follicular and luteal phases, respectively. In the letrozole group versus placebo group, testosterone increased by 79% (95% CI [55%; 105%], P < 0.0001) and 49% (95% CI [30%; 72%], P < 0.0001) in the follicular and luteal phases, respectively. In the letrozole group versus placebo group, the increase in androstenedione was by 85% (95% CI [59%; 114%], P < 0.0001) and 69% (95% CI [48%; 94%], P < 0.0001) in the follicular and luteal phases, respectively. The ongoing pregnancy rate was similar between the letrozole and placebo groups (31% vs 39% (risk-difference of 8%, 95% CI [-25%; 11%], P = 0.55)). No serious adverse reactions were recorded in either group. The total duration of exogenous FSH stimulation was 1 day shorter in the intervention group, significantly reducing total FSH consumption (mean difference -100 IU, 95% CI [-192; -21], P = 0.03).

LIMITATIONS, REASONS FOR CAUTION

Late follicular progesterone samples were collected on the day before and day of ovulation triggering for patient logistic considerations, and the recently emerged knowledge about diurnal variation of progesterone was not taken into account. The study was powered to detect hormonal variations but not differences in pregnancy outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

Although the use of letrozole has no effect on the primary outcome, the number of women with a premature increase in progesterone on the day of ovulation triggering, the increased progesterone in the mid-luteal phase due to letrozole may contribute to optimizing the luteal phase endocrinology. The effect of letrozole on increasing androgens and reducing FSH consumption may be used in poor responders. However, the effect of letrozole on implantation and ongoing pregnancy rates should be evaluated in a meta-analysis or larger randomized controlled trial (RCT).

STUDY FUNDING/COMPETING INTEREST(S)

Funding was received from EU Interreg for ReproUnion and Ferring Pharmaceuticals, and Roche Diagnostics contributed with assays. N.S.M. and A.P. have received grants from Ferring, Merck Serono, Anecova and Gedeon Richter, and/or personal fees from IBSA, Vivoplex, ArtPred and SPD, outside the submitted work. The remaining authors have no competing interests.

TRIAL REGISTRATION NUMBERS

NCT02939898 and NCT02946684.

TRIAL REGISTRATION DATE

15 August 2016.

DATE OF FIRST PATIENT’S ENROLMENT

22 August 2016.

Ovarian Reserve Biomarkers and Menstrual Cycle Length in a Prospective Cohort Study

CONTEXT

While age-related changes in menstrual cycle length are well known, it is unclear whether anti-Müllerian (AMH) or other ovarian reserve biomarkers have a direct association with cycle length.

OBJECTIVE

To determine the association between biomarkers of ovarian reserve and menstrual cycle length.

METHODS

Secondary analysis using data from time to conceive (TTC), a prospective time to pregnancy cohort study. The age-independent association between cycle length and biomarkers of ovarian reserve was analyzed using linear mixed and marginal models. Study participants were TTC-enrolled women aged 30-44 years with no history of infertility who were attempting to conceive for <3 months were enrolled. Serum AMH, follicle-stimulating hormone, and inhibin B levels were measured on cycle day 2, 3, or 4. Participants recorded daily menstrual cycle data for ≤4 months. The primary outcome was menstrual cycle length; follicular and luteal phase lengths were secondary outcomes.

RESULTS

Multivariable analysis included 1880 cycles from 632 women. Compared with AMH levels of 1.6 to 3.4 ng/mL, women with AMH <1.6 ng/mL had cycles and follicular phases that were 0.98 (95% CI -1.46, -0.50) and 1.58 days shorter (95% CI -2.53, -0.63), respectively, while women with AMH >8 ng/mL had cycles that were 2.15 days longer (95% CI 1.46, 2.83), follicular phases that were 2 days longer (95% CI 0.77, 3.24), and luteal phases that were 1.80 days longer (95% CI 0.71, 2.88).

CONCLUSION

Increasing AMH levels are associated with longer menstrual cycles due to both a lengthening of the follicular and the luteal phase independent of age.

Recombinant human luteinizing hormone co-treatment in ovarian stimulation for assisted reproductive technology in women of advanced reproductive age: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Several studies suggest that luteinizing hormone (LH) could improve IVF outcome in women of advanced reproductive age by optimizing androgen production. In this review, we assessed the role of recombinant-human LH (r-hLH) and recombinant human follicle stimulating hormone (r-hFSH) co-treatment in ovarian stimulation for assisted reproductive technology in women of advanced reproductive age candidates for assisted reproduction.

MATERIAL AND METHODS

Using a preregistered protocol we systematically searched Medline/PubMed, Scopus and the ISI Web of Science databases to identify randomized controlled trials in which r-hFSH monotherapy protocols were compared with r-hFSH/r-hLH co-treatment in women ≥35 years undergoing fresh IVF cycles. We calculated the pooled odds ratio (OR) for dichotomous data and the weight mean difference (WMD) for continuous data with an associated 95% confidence interval (CI). The meta-analyses were conducted using the random-effect model. P values < 0.05 were considered statistically significant. Subgroup analyses of all primary and secondary outcomes were performed only in women aged 35-40 years.

RESULTS

Twelve studies were identified. In women aged between 35 and 40 years, r-hFSH/r-hLH co-treatment was associated with higher clinical pregnancy rates (OR 1.45, CI 95% 1.05-2.00, I² = 0%, P = 0.03) and implantation rates (OR 1.49, CI 95% 1.10-2.01, I² = 13%, P = 0.01) versus r-hFSH monotherapy. Fewer oocytes were retrieved in r-hFSH/r-hLH-treated patients than in r-hFSH-treated patients both in women aged ≥35 years (WMD -0.82 CI 95% -1.40 to - 0.24, I² = 88%, P = 0.005) and in those aged between 35 and 40 years (WMD -1.03, CI - 1.89 to - 0.17, I² = 0%, P = 0.02). The number of metaphase II oocytes, miscarriage rates and live birth rates did not differ between the two groups of women overall or in subgroup analysis.

CONCLUSION

Although more oocytes were retrieved in patients who underwent r-hFSH monotherapy, this meta-analysis suggests that r-hFSH/r-hLH co-treatment improves clinical pregnancy and implantation rates in women between 35 and 40 years of age undergoing ovarian stimulation for assisted reproduction technology. However, more RCTs using narrower age ranges in advanced age women are warranted to corroborate these findings.

Follicular hormone dynamics during the midcycle surge of gonadotropins in women undergoing fertility treatment

Changes in concentrations of intra-follicular hormones during ovulation are important for final oocyte maturation and endometrial priming to ensure reproductive success. As no human studies have investigated these changes in detail, our objective was to describe the dynamics of major follicular fluid (FF) hormones and transcription of steroidogenic enzymes and steroid receptors in human granulosa cells (GCs) during ovulation. We conducted a prospective cohort study at a public fertility clinic in 2016-2018. Fifty women undergoing ovarian stimulation for fertility treatment were included. From each woman, FF and GCs were collected by transvaginal ultrasound-guided follicle puncture of one follicle at two specific time points during ovulation, and the study covered a total of five time points: before ovulation induction (OI), 12, 17, 32 and 36 h after OI. Follicular fluid concentrations of oestradiol, progesterone, androstenedione, testosterone, 17-hydroxyprogesterone, anti-Mullerian hormone, inhibin A and inhibin B were measured using ELISA assays, and a statistical mixed model was used to analyse differences in hormone levels between time points. Gene expression of 33 steroidogenic enzymes and six hormone receptors in GCs across ovulation were assessed by microarray analysis, and selected genes were validated by quantitative reverse transcription PCR. We found that concentrations of oestradiol, testosterone, progesterone, AMH, inhibin A and inhibin B (P < 0.001) and gene expression of 12 steroidogenic enzymes and five receptors (false discovery rate < 0.0001) changed significantly during ovulation. Furthermore, we found parallel changes in plasma hormones. The substantial changes in follicular hormone production during ovulation highlight their importance for reproductive success.

The role of pituitary gonadotropins and intraovarian regulators in follicle development: A mini-review

BACKGROUND

The process of follicle development is tightly regulated by pituitary gonadotropins (follicle-stimulating hormone [FSH] and luteinizing hormone [LH]) and intraovarian regulators (eg, steroids, growth factors, and cytokines).

METHODS

This review outlines recent findings on the mechanisms of human follicle development, based on the research on animal models such as mice, rats, cows, and sheep.

MAIN FINDINGS

Phosphatidylinositol 3-kinase/protein kinase B signaling pathway and anti-Müllerian hormone are involved in primordial follicle activation during the gonadotropin-independent phase. The intraovarian regulators, such as androgen, insulin-like growth factor system, activin, oocyte-derived factors (growth differentiation factor-9 and bone morphogenetic protein 15), and gap junction membrane channel protein (connexin), play a central role in the acquisition of FSH dependence in preantral follicles during the gonadotropin-responsive phase. Antral follicle development can be divided into FSH-dependent growth and LH-dependent maturation. The indispensable tetralogy for follicle selection and final maturation of antral follicles involves (a) acquisition of LH dependence, (b) greater capacity for E2 production, (c) activation of the IGF system, and (d) an antiapoptotic follicular microenvironment.

CONCLUSION

We reproductive endocrinologists should accumulate further knowledge from animal model studies to develop methods that promote early folliculogenesis and connect to subsequent gonadotropin therapy in infertile women.

Ovarian Reserve Markers in Premature Ovarian Insufficiency: Within Different Clinical Stages and Different Etiologies

OBJECTIVE

To characterize the ovarian reserve indicators for premature ovarian insufficiency (POI) at different disease stages and with various etiologies.

METHODS

According to different FSH levels and menstrual conditions, patients with normal ovarian reserve (NOR with 5 IU/L<FSH<10 IU/L, n=987), precursor stage of POI (pre-POI with 10 IU/L<FSH ≤ 25 IU/L, n=410), early POI (25 IU/L<FSH ≤ 40 IU/L n=147), and premature ovarian failure (POF with FSH>40 IU/L, n=454) were retrospectively screened and their records were abstracted from Reproductive Hospital Affiliated to Shandong University between 2014 and 2019. Based on the known etiologies, POI patients were subdivided into genetic, iatrogenic, autoimmune and idiopathic subsets according to the known etiologies. The phenotypic features were compared within different subgroups, and the predictive value of ovarian reserve markers was analyzed.

RESULTS

The ovarian reserve indicators consecutively deteriorated with the progress of ovarian insufficiency, indicated as an increase of FSH and LH but decrease of AMH, inhibin B, AFC, E₂ and T (P<0.01). Most of them changed significantly from NOR to pre-POI while remained relatively stable at a low level or even undetectable at early POI and POF stage. AMH showed the highest predictive value for pre-POI (AUC 0.932, 95% CI 0.918-0.945) and POI (AUC 0.944, 95% CI 0.933-0.954), and the combination of AMH and AFC was highly promising for early prediction. Additionally, significant differences existed in AMH, inhibin B and AFC among women with different etiologies of POI (P<0.05), and the genetic POI presented the worst hormone status.

CONCLUSIONS

Our study indicated a high heterogeneity of POI in both endocrine hormones and etiological phenotypes. The quantitative changes and cutoff values of AMH and AFC could provide new insights in the prediction and early diagnosis of POI.

Letrozole for Female Infertility

Letrozole, an aromatase inhibitor that blocks estrogen synthesis by inhibiting the final step of the estrogen biosynthetic pathway, has been used in the applications of a wide range of infertility settings. It has been more than 20 years since the initial clinical trial of letrozole for ovulation induction. In light of the accumulating clinical and basic evidence, the efficacy and safety of letrozole have been identified. This mini review focuses on our current knowledge of the applications and mechanisms of letrozole for female infertility and various questions are put forward about how letrozole could be more effectively used.

A novel mathematical model of true ovarian reserve assessment based on predicted probability of poor ovarian response: a retrospective cohort study

PURPOSE

To establish a mathematical model for assessing the true ovarian reserve based on the predicted probability of poor ovarian response (POR).

METHODS

In this retrospective cohort study, a total of 1523 GnRH-antagonist cycles in 2017 were firstly analyzed. The ovarian responses were calculated based on the number of retrieved oocytes. The continuous variables were converted into categorical variables according to cutoff values generated by the decision tree method. The optimal model was identified using forward stepwise multiple logistic regression with 5-fold cross-validation and further verified its performances using outer validation data.

RESULTS

The predictors in our model were anti-Müllerian hormone (AMH), antral follicle counts (AFC), basal follicle-stimulating hormone (FSH), and age, in order of their significance, named AAFA model. The AUC, sensitivity, specificity, positive predictive value, and negative predictive value of AAFA model in inner validation and outer validation data were 0.861 and 0.850, 0.603 and 0.519, 0.917 and 0.930, 0.655 and 0.570, and 0.899 and 0.915. Ovarian reserve of 16 subgroups was further ranked according to the predicted probability of POR and further divided into 4 groups of A-D using clustering analysis. The incidence of POR in the four groups was 0.038 (0.030-0.046), 0.139 (0.101-0.177), 0.362 (0.308-0.415), and 0.571 (0.525-0.616), respectively. The order of ovarian reserve from adequate to poor followed the order of A to D.

CONCLUSION

We have established an easy applicable AAFA model for assessing true ovarian reserve and may have important implications in both infertile women and general reproductive women in Chinese or Asian population.

Ovarian hyperstimulation closely associated with resumption of follicular growth after chemotherapy during tamoxifen treatment in premenopausal women with breast cancer: a multicenter retrospective cohort study

Background

We previously reported that tamoxifen (TAM)-induced ovarian hyperstimulation (OHS) is associated with high serum concentrations of estradiol in premenopausal women with breast cancer. To investigate risk factors for TAM-induced OHS, we performed a retrospective multicenter study.

Methods

Premenopausal patients who received surgical therapy for endocrine-dependent breast cancer (n = 235) were recruited in this study and classified into 4 groups: group A, treated with TAM alone; group B, TAM treatment after 2-year-combined therapy with a gonadotropin-releasing hormone (Gn-RH) agonist; group C, TAM treatment after chemotherapy; group D, 5-year-combined therapy with TAM and a Gn-RH agonist. A serum estradiol value of more than 300 pg/mL or mean follicular diameter of more than 30 mm was defined as OHS.

Results

The incidence of OHS in group A (n = 13/26, 50.0%) was significantly higher than those in group B (n = 17/63, 27.0%), group C (n = 20/110, 18.2%), and group D (n = 0/36, 0%). The incidence of OHS was significantly correlated with aging, and the median serum concentration of estradiol in the presence of OHS was 823.0 pg/mL. The incidence of OHS (less than 47 years old) was 62.5% in group A, 48.6% in group B, and 28.2% in group C, respectively. Notably, the incidence rate of OHS following amenorrhea in group C (n = 13/20, 65.0%) was significantly higher than that in group B (n = 1/17, 5.9%).

Conclusions

These findings indicate that the onset of OHS following amenorrhea was common in the post-chemotherapeutic group, while its ratio was low in the group after Gn-RH analog treatment, suggesting that combined treatment-based management involving TAM therapy is necessary for premenopausal patients with breast cancer.

Neuroendocrine, autocrine, and paracrine control of follicle-stimulating hormone secretion

Follicle-stimulating hormone (FSH) is a glycoprotein hormone produced by gonadotropes in the anterior pituitary that plays a central role in controlling ovarian folliculogenesis and steroidogenesis in females. Moreover, recent studies strongly suggest that FSH exerts extragonadal actions, particularly regulating bone mass and adiposity. Despite its crucial role, the mechanisms regulating FSH secretion are not completely understood. It is evident that hypothalamic, ovarian, and pituitary factors are involved in the neuroendocrine, paracrine, and autocrine regulation of FSH production. Large animal models, such as the female sheep, represent valuable research models to investigate specific aspects of FSH secretory processes. This review: (i) summarizes the role of FSH controlling reproduction and other biological processes; (ii) discusses the hypothalamic, gonadal, and pituitary regulation of FSH secretion; (iii) considers the biological relevance of the different FSH isoforms; and (iv) summarizes the distinct patterns of FSH secretion under different physiological conditions.

Biological and Clinical Rationale for Androgen Priming in Ovarian Stimulation

Androgen receptors are expressed by all stages of growing follicles, and follicular fluid androgen levels are positively correlated to granulosa cell androgen receptor and follicle-stimulating hormone (FSH) receptor expression. Thus, androgens may promote follicular growth, accumulation and/or responsiveness to gonadotropins. This is explored therapeutically in the concept of androgen priming, to improve the ovarian response to stimulation in assisted reproduction. Androgen effects may be achieved in two different ways, either directly by providing exogenous androgen or by providing luteinizing hormone (LH) activity [i.e., LH or human chorionic gonadotropin (hCG)] to stimulate local ovarian production of androgen. The androgen concentrations in follicular fluid by far exceed the levels in female circulation and it has recently been shown that there was no correlation between serum testosterone levels and follicular fluid androgen levels. There is some evidence that administration of exogenous dehydroepiandrosterone or testosterone increases live birth rates, but an optimal protocol has not been established and such adjuvant treatment should be considered experimental. Furthermore, studies exploring long-term administration of LH activity, achieving LH levels comparable to those seen in women with polycystic ovary syndrome, are awaited. The aim of the present review is to discuss critically the most suitable approach for androgen priming from a biological and clinical standpoint, and to evaluate current approaches and results obtained in clinical trials.

Inhibin A-A Promising Predictive Parameter for Determination of Final Oocyte Maturation in Ovarian Stimulation for IVF/ICSI

The number of mature oocytes is a key factor in the success of Assisted Reproductive Techniques (ART). Exogenous gonadotropins are administered during ovarian stimulation in order to maximize the number of oocytes available for fertilization. During stimulation, monitoring is mandatory to evaluate individual response, to avoid treatment complications and assist in the determination of the optimal day for final oocyte maturation and oocyte retrieval. Routine monitoring during stimulation includes transvaginal ultrasound examinations and measurement of serum estradiol (E2). Due to multifollicular growth of follicles of varying size, serum E2 levels are commonly supraphysiological and often variable, rendering E2-measurement during ovarian stimulation unreliable as a determinant of oocyte maturity. In contrast to serum E2, serum Inhibin A levels increase once a minimum follicle size of 12-15 mm is achieved. Due to this fact, serum Inhibin A levels could present in combination with ultrasound monitoring a more reliable parameter to determine the optimal follicle size for final oocyte maturation, as only follicles with a size of 12 mm and beyond will contribute to the serum Inhibin A level. This prospective observational, cross-sectional study demonstrates, that on the day of final oocyte maturation serum Inhibin A is strongly correlated to the number of follicles ≥15 mm (0.72) and to the number of retrieved and mature oocytes (ρ 0.82/0.77, respectively), whereas serum E2 is moderately correlated to the parameters mentioned above (ρ 0.64/0.69/0.69, respectively). With an area under the curve (AUC) of 0.91 for Inhibin A, compared to an AUC of 0.84 for E2, Inhibin A can be regarded as a better predictor for the optimal timing of trigger medication with a threshold number of ≥10 mature oocytes. It can be concluded from this data that serum Inhibin A in combination with transvaginal ultrasound monitoring may be a more powerful tool in the decision making process on trigger timing as compared to E2.

A Tale of Two Proteins: Betaglycan, IGSF1, and the Continuing Search for the Inhibin B Receptor

Inhibins are gonadal hormones that suppress follicle-stimulating hormone (FSH) synthesis by pituitary gonadotrope cells. The structurally related activins stimulate FSH by signaling through complexes of type I and type II receptors. Two models of inhibin action were proposed in 2000. First, inhibins function as competitive receptor antagonists, binding activin type II receptors with high affinity in the presence of the TGF-β type III coreceptor, betaglycan. Second, immunoglobulin superfamily, member 1 (IGSF1, then called p120) was proposed to mediate inhibin B antagonism of activin signaling via its type I receptor. These ideas have been challenged over the past few years. Rather than playing a role in inhibin action, IGSF1 is involved in the central control of the thyroid gland. Betaglycan binds inhibin A and inhibin B with high affinity, but only functions as an obligate inhibin A coreceptor in murine gonadotropes. There is likely to be a distinct, but currently unidentified coreceptor for inhibin B.

Quantitative Differences in TGF-β Family Members Measured in Small Antral Follicle Fluids From Women With or Without PCO

CONTEXT

Members of the TGF-β family have been implicated in aberrant follicle development in women with polycystic ovaries (PCO).

OBJECTIVE

Are there quantitative differences in the concentrations of TGF-β family members in fluid from human small antral follicles (hSAFs) in women with or without PCO?

DESIGN AND SETTING

Follicle fluids (FFs) were collected from 4- to 11-mm hSAFs obtained from women undergoing ovarian tissue cryopreservation for fertility preservation.

PATIENTS

FFs from 16 women with PCO (FF = 93) and 33 women without PCO (FF = 92).

MAIN OUTCOME MEASURES

Intrafollicular concentrations of growth differentiation factor-9 (GDF9); anti-Müllerian hormone (AMH); inhibin-A and inhibin-B; total inhibin; activin-A, activin-B, and activin-AB; follistatin; follistatin-like-3; estradiol; and testosterone.

RESULTS

Activin-B concentrations were reported in hSAFs, and concentrations were 10 times higher than activin-A and activin-AB concentrations. Activin-B showed significant associations with other growth factors. Concentrations of inhibin-A and inhibin-B were significantly lower in FFs from women with PCO, especially in hSAFs <8 mm in diameter. AMH concentrations did not differ between the groups in hSAFs <8 mm; however, AMH remained high in hSAFs >8 mm in women with PCO but decreased in women without PCO. Estradiol was significantly lower in FFs from women with PCO and showed significant associations with AMH. Concentrations of GDF9 showed significantly higher concentrations in PCO FFs of follicles >6 mm.

CONCLUSIONS

Altered concentrations of TGF-β family members in hSAFs from women with PCO highlight altered growth factor signaling as a potential mechanism for follicle growth arrest.

Progressive changes in human follicular fluid composition over the course of ovulation: quantitative proteomic analyses

Follicular fluid (FF) acts as a vehicle for paracrine signalling between somatic cells of the follicle and the oocyte. To investigate changes in the protein composition of FF during ovulation, we conducted a prospective cohort study including 25 women undergoing fertility treatment. Follicular fluid was aspirated either before or 12, 17, 32 or 36 h after induction of ovulation (five patients per time point). Liquid chromatography-mass spectrometry was used to identify and quantify FF proteins. In total, 400 proteins were identified and the levels of 40 proteins changed significantly across ovulation, evaluated by analysis of covariance (adjusted p < 0.05) and on-off expression patterns. The majority peaked after 12-17 h, e.g., AREG (p < 0.0001), TNFAIP6 (p < 0.0001), and LDHB (p = 0.0316), while some increased to peak after 36 h e.g., ACPP (p < 0.0001), TIMP1 (p < 0.0001) and SERPINE1 (p = 0.0002). Collectively, this study highlights proteins and pathways of importance for ovulation and oocyte competence in humans.

Polyinosinic-polycytidylic acid induces innate immune responses via Toll-like receptor 3 in human ovarian granulosa cells

The ovary can be infected by a variety of viruses, which may come from the female reproductive tract or the peritoneum. The innate immune responses to viral infection in the human ovary are poorly understood. The present study demonstrated that human ovarian granulosa cells had innate immune activity in response to viral RNA challenge through Toll-like receptor 3 (TLR3) activation. TLR3 was constitutively expressed in the human ovary and predominantly located in granulosa cells of developmental follicles at all stages. Polyinosinic-polycytidylic acid [poly (I:C)], a synthetic viral double-stranded RNA analog, induced innate immune responses in human ovarian granulosa cells and affected endocrine function. Poly (I:C) significantly upregulated proinflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1β and type I interferon (IFN-α/β), and the innate immune responses were significantly reduced by blocking TLR3 signaling. Furthermore, poly (I:C) induced antiviral genes expression, including 2'-5'-oligoadenylate synthetase, Mx GTPase 1, IFN-stimulating gene 15 and double-stranded RNA-activated protein kinase R. In contrast, the expression of P450 aromatase and inhibin was dramatically inhibited by poly (I:C). Both silencing of TLR3 and neutralizing TNF-α reversed the inhibitory effect of poly (I:C) on P450 aromatase and inhibin expression. Our study demonstrates that granulosa cells play a potential role in innate immune protection against viral infection in the normal human ovary, and the innate immune response perturbs cell endocrine function.

Anti-müllerian hormone compared with other ovarian markers after childhood cancer treatment

BACKGROUND

Gonadal dysfunction is one of the major late complications after cancer diagnosis and treatment. The best markers of ovarian reserve in clinical practice are antral follicle count (AFC) and ovarian volume. We aimed to study the prevalence of premature ovarian insufficiency (POI) and evaluate anti-Müllerian hormone (AMH) and other serum markers for ovarian function in adult women who were childhood cancer survivors (CCS) in comparison with a control group.

MATERIAL AND METHODS

Altogether, 167 female CCS were compared to 164 matched controls. Prevalence of POI was documented and serum levels of AMH, inhibin B, follicle stimulating hormone (FSH), and estradiol (E2) were compared with AFC and ovarian volume.

RESULTS

POI was reported in 22 (13%) of the CCS and in none of the controls. Serum levels of AMH, inhibin B, and FSH, but not E2, correlated significantly with AFC and ovarian volume; AMH showed the highest correlation. There was no difference between CCS and controls regarding the different serum markers as measured by linear regression analysis. ROC curve AUC for primary POI showed the highest values for AMH (0.930) and AFC (0.944). For AFC <10, ROC curve AUC showed highest value for AMH for CCS (0.866) and controls (0.878). In a subgroup of female CCS <40 years (n = 120), the results were similar.

CONCLUSION

We found POI in 13% among CCS, slightly more than in other studies. Serum levels of AMH, inhibin B, and FSH correlated significantly with AFC and ovarian volume, and no difference was noted between CCS and controls. AMH was the most reliable serum marker for ovarian function in terms of POI and low AFC.

Recombinant luteinizing hormone supplementation in assisted reproductive technology: a systematic review

OBJECTIVE

To assess the role of recombinant human LH (r-hLH) supplementation in ovarian stimulation for ART in specific subgroups of patients.

DESIGN

Systematic review.

SETTING

Centers for reproductive care.

PATIENT(S)

Six populations were investigated: 1) women with a hyporesponse to recombinant human FSH (r-hFSH) monotherapy; 2) women at an advanced reproductive age; 3) women cotreated with the use of a GnRH antagonist; 4) women with profoundly suppressed LH levels after the administration of GnRH agonists; 5) normoresponder women to prevent ovarian hyperstimulation syndrome; and 6) women with a "poor response" to ovarian stimulation, including those who met the European Society for Human Reproduction and Embryology Bologna criteria.

INTERVENTION(S)

Systematic review.

MAIN OUTCOME MEASURE(S)

Implantation rate, number of oocytes retrieved, live birth rate, ongoing pregnancy rate, fertilization rate, and number of metaphase II oocytes.

RESULT(S)

Recombinant hLH supplementation appears to be beneficial in two subgroups of patients: 1) women with adequate prestimulation ovarian reserve parameters and an unexpected hyporesponse to r-hFSH monotherapy; and 2) women 36-39 years of age. Indeed, there is no evidence that r-hLH is beneficial in young (<35 y) normoresponders cotreated with the use of a GnRH antagonist. The use of r-hLH supplementation in women with suppressed endogenous LH levels caused by GnRH analogues and in poor responders remains controversial, whereas the use of r-hLH supplementation to prevent the development of ovarian hyperstimulation syndrome warrants further investigation.

CONCLUSION(S)

Recombinant hLH can be proposed for hyporesponders and women 36-39 years of age.

The polymorphic insertion of the luteinizing hormone receptor "insLQ" show a negative association to LHR gene expression and to the follicular fluid hormonal profile in human small antral follicles

The luteinizing hormone receptor (LHCGR) has a little studied polymorphic 6 bp insertion (rs4539842/insLQ). This study has evaluated the insLQ polymorphism in relation to potential associations with hormonal characteristics of human small antral follicles (hSAFs). In total, 310 hSAFs were collected from 86 women undergoing fertility preservation. Analysis included hormonal profile of 297 follicular fluid (FF) samples and 148 corresponding granulosa cells samples were evaluated by qPCR for selected genes. Significantly reduced and non-detectable mRNA levels of anti-Müllerian hormone receptor II (AMHR2) and LHCGR, respectively, were observed for insLQ/insLQ compared to -/insLQ and the -/- genotypes. Moreover, LHCGR and CYP19a1 together with oestradiol and inhibin-B were significantly increased in -/insLQ compared to the -/- genotype. The homozygous insLQ genotype showed strong significant associations to GC specific genes LHCGR and CYP19a1, which may translate into significant changes in FF hormone profiles and an altered LH signaling.

Extraovarian gonadotropin negative feedback revealed by aromatase inhibition in female marmoset monkeys

Whereas the ovary produces the majority of estradiol (E₂) in mature female primates, extraovarian sources contribute to E₂ synthesis and action, including the brain E₂-regulating hypothalamic gonadotropin-releasing hormone. In ovary-intact female rodent models, aromatase inhibition (AI) induces a polycystic ovary syndrome-like hypergonadotropic hyperandrogenism due to absent E₂-mediated negative feedback. To examine the role of extraovarian E₂ on nonhuman primate gonadotropin regulation, the present study uses letrozole to elicit AI in adult female marmoset monkeys. Sixteen female marmosets (Callithrix jacchus; >2 yr) were randomly assigned to ovary-intact or ovariectomy (OVX) conditions and subsequently placed on a daily oral regimen of either ~200 µl vehicle alone (ovary-intact Control, n = 3; OVX, n = 3) or 1 mg ⋅ kg^-1 ⋅ day^-1 letrozole in vehicle (ovary-intact AI, n = 4; OVX + AI, n = 6). Blood samples were collected every 10 days, and plasma chorionic gonadotropin (CG) and steroid hormone levels were determined by validated radioimmunoassay and liquid chromatography/tandem mass spectrometry, respectively. Ovary-intact, AI-treated and OVX females exhibited elevated CG (P < 0.01, P = 0.004, respectively) compared with controls, and after 30 days, OVX + AI females exhibited a suprahypergonadotropic phenotype (P = 0.004) compared with ovary-intact + AI and OVX females. Androstenedione (P = 0.03) and testosterone (P = 0.05) were also elevated in ovary-intact, AI-treated females above all other groups. The current study thus confirms in a nonhuman primate that E₂ depletion and diminished negative feedback in ovary-intact females engage hypergonadotropic hyperandrogenism. Additionally, we demonstrate that extraovarian estrogens, possibly neuroestrogens, contribute to female negative feedback regulation of gonadotropin release.

Hallmarks of Human Small Antral Follicle Development: Implications for Regulation of Ovarian Steroidogenesis and Selection of the Dominant Follicle

Regulation of human ovarian steroidogenesis differs from other species and precise knowledge on how human small antral follicles (hSAF) develop and acquire competence for continued growth and steroid output is still incomplete. The present study has characterized almost 1,000 normal hSAF collected in connection with cryopreservation of ovarian tissue for fertility preservation. The antral follicles (ranging from 3 to 13 mm) were generally aspirated from one ovary surgically removed during the natural cycle, and the follicular fluid (FF) and the granulosa cells (GC) were isolated and snap-frozen. In FF, the following hormones were measured: inhibin-B, inhibin-A, AMH, follistatin, PAPP-A, estradiol, progesterone, testosterone, and androstenedione. In GC, mRNA gene expressions using q-PCR were measured for the following genes: FSHR, AMH, CYP19, and AR. All samples in which one of the abovementioned parameters was measured were included, but typically multiple parameters were measured. Highly significant differences in concentration and follicular content in relation to follicular diameter were found for all measured hormones despite massive variability in-between follicles for any given diameter. The results demonstrate that profound changes take place in the hormonal microenvironment around follicular diameters of 8-11 mm corresponding to when follicular selection occurs. At this point, inhibin-B and inhibin-A showed distinct peaks concomitant with a significant reduction in both AMH protein and mRNA expression. Concentrations of inhibins, androgens, FSHR, and AR were intimately associated, and it is suggested that inhibin-B in combination with PAPP-A and thereby IGF2 activity exerts important paracrine signaling at follicular selection. At the same time upregulation of estradiol synthesis and CYP19 mRNA expression increased steroid output profoundly. Furthermore, the highly significant association between FSHR and AR mRNA gene expression enforces important functions of androgens in follicular development. Collectively, these data reintroduce the understanding of the follicular phase as two parted in which regulation of steroidogenesis differs. The profound changes taking place around follicular selection highlight important paracrine actions of TGF-β family members and IGFs for securing dominance of the selected follicle.

The Common Follicle-Stimulating Hormone Receptor (FSHR) Promoter Polymorphism FSHR -29G > A Affects Androgen Production in Normal Human Small Antral Follicles

Follicle-stimulating hormone receptors (FSHRs) are almost exclusively expressed on granulosa cells, and FSH action is probably most clearly reflected in intrafollicular hormone milieu of antral follicles. Little is known about the possible effects of the common single nucleotide polymorphism (SNP) FSHR -29G > A (rs1394205) on hormonal conditions in humsan small antral follicles (hSAFs) obtained from women in the natural menstrual cycle. This study investigated the follicle fluid (FF) concentrations of anti-Müllerian hormone, estradiol, progesterone, androstenedione, and testosterone in hSAF in relation to the different genotypes of FSHR -29G > A. FF from 362 follicles was collected in 95 women undergoing fertility preservation, who did not suffer from a disease that directly affected ovarian function. The testosterone levels of the minor A/A genotype were significantly increased compared to the A/G and the G/G genotype. Furthermore, significantly reduced androstenedione levels were observed for the G/G genotype, as compared to the A/G genotype, while the other hormones did not show statistical significant differences. In conclusion, the androgen levels of hSAF were significantly elevated in the minor SNP genotype in the FSHR promoter polymorphism FSHR -29G > A.