Ambient ozone and ovarian reserve in Chinese women of reproductive age: Identifying susceptible exposure windows

Little is known about the association of ambient ozone with ovarian reserve. Based on a retrospective cohort study of 6008 women who attended a fertility center in Hubei, China, during 2018-2021, we estimated ozone exposure levels by calculating averages during the development of follicles (2-month [W1], 4-month [W2], 6-month [W3]) and 1-year before measurement (W4) according to Tracking Air Pollution in China database. We used multivariate logistic regression and linear regression models to investigate association of ozone exposure with anti-müllerian hormone (AMH), the preferred indicator of ovarian reserve. Each 10 μg/m3 increases in ozone were associated with 2.34% (0.68%, 3.97%), 2.08% (0.10%, 4.01%), 4.20% (1.67%, 6.67%), and 8.91% (5.79%, 11.93%) decreased AMH levels during W1-W4; AMH levels decreased by 15.85%, 11.90%, 16.92% in the fourth quartile during W1, W3, and W4 when comparing the extreme quartile, with significant exposure-response relationships during W4 (P < 0.05). Ozone exposure during W1 was positively associated with low AMH. Additionally, we detected significant effect modification by age, body mass index, and temperature in ozone-associated decreased AMH levels. Our findings highlight the potential adverse impact of ozone pollution on female ovarian reserve, especially during the secondary to small antral follicle stage and 1-year before measurement.

AMH Regulation by Steroids in the Mammalian Testis: Underlying Mechanisms and Clinical Implications

Anti-Müllerian hormone (AMH) is a distinctive biomarker of the immature Sertoli cell. AMH expression, triggered by specific transcription factors upon fetal Sertoli cells differentiation independently of gonadotropins or sex steroids, drives Müllerian duct regression in the male, preventing the development of the uterus and Fallopian tubes. AMH continues to be highly expressed by Sertoli until the onset of puberty, when it is downregulated to low adult levels. FSH increases testicular AMH output by promoting immature Sertoli cell proliferation and individual cell expression. AMH secretion also showcases a differential regulation exerted by intratesticular levels of androgens and estrogens. In the fetus and the newborn, Sertoli cells do not express the androgen receptor, and the high androgen concentrations do not affect AMH expression. Conversely, estrogens can stimulate AMH production because estrogen receptors are present in Sertoli cells and aromatase is stimulated by FSH. During childhood, sex steroids levels are very low and do not play a physiological role on AMH production. However, hyperestrogenic states upregulate AMH expression. During puberty, testosterone inhibition of AMH expression overrides stimulation by estrogens and FSH. The direct effects of sex steroids on AMH transcription are mediated by androgen receptor and estrogen receptor α action on AMH promoter sequences. A modest estrogen action is also mediated by the membrane G-coupled estrogen receptor GPER. The understanding of these complex regulatory mechanisms helps in the interpretation of serum AMH levels found in physiological or pathological conditions, which underscores the importance of serum AMH as a biomarker of intratesticular steroid concentrations.

Translational Physiology of Anti-Müllerian Hormone: Clinical Applications in Female Fertility Preservation and Cancer Treatment

Background

Whilst the ability of AMH to induce the regression of the Müllerian ducts in the male fetus is well appreciated, AMH has additional biological actions in relation to steroid biosynthesis and ovarian follicle dynamics. An understanding of the physiology of AMH illuminates the potential therapeutic utility of AMH to protect the ovarian reserve during chemotherapy and in the treatment of female malignancies. The translation of the biological actions of AMH into clinical applications is an emerging focus of research, with promising preliminary results.

Objective and Rationale

Studies indicate AMH restrains primordial follicle development, thus administration of AMH during chemotherapy may protect the ovarian reserve by preventing the mass activation of primordial follicles. As AMH induces regression of tissues expressing the AMH receptor (AMHRII), administration of AMH may inhibit growth of malignancies expressing AMHR II. This review evaluates the biological actions of AMH in females and appraises human clinical applications.

Search Methods

A comprehensive search of the Medline and EMBASE databases seeking articles related to the physiological functions and therapeutic applications of AMH was conducted in July 2021. The search was limited to studies published in English.

Outcomes

AMH regulates primordial follicle recruitment and moderates sex steroid production through the inhibition of transcription of enzymes in the steroid biosynthetic pathway, primarily aromatase and 17α-hydroxylase/17,20-lyase. Preliminary data indicates that administration of AMH to mice during chemotherapy conveys a degree of protection to the ovarian reserve. Administration of AMH at the time of ovarian tissue grafting has the potential to restrain uncontrolled primordial follicle growth during revascularization. Numerous studies demonstrate AMH induced regression of AMHR II expressing malignancies. As this action occurs via a different mechanism to traditional chemotherapeutic agents, AMH has the capacity to inhibit proliferation of chemo-resistant ovarian cancer cells and cancer stem cells.

Wider Implications

To date, AMH has not been administered to humans. Data identified in this review suggests administration of AMH would be safe and well tolerated. Administration of AMH during chemotherapy may provide a synchronistic benefit to women with an AMHR II expressing malignancy, protecting the ovarian reserve whilst the cancer is treated by dual mechanisms.

Anti-Müllerian Hormone Accelerates Pathological Process of Insulin Resistance in Polycystic Ovary Syndrome Patients

Insulin resistance (IR) is one of the most common features of polycystic ovary syndrome (PCOS), which is related to obesity. Whether increased anti-Müllerian hormone (AMH) levels in PCOS are involved in the pathogenesis of insulin resistance remains unclear. We investigated serum levels of leptin and AMH along with basic clinical and metabolic parameters in 114 PCOS patients and 181 non-PCOS women. PCOS patients presented higher fasting blood glucose, insulin concentrations and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) in addition to body mass index (BMI), lipids profiles and hormone levels. HOMA-IR showed a positive correlation with BMI, AMH, leptin, and low-density lipoprotein-cholesterol (LDL-c) levels. Interestingly, AMH is strongly positively correlated with HOMA-IR and insulin concentrations for 1st and 2nd hours of glucose treatment after fasting. Among PCOS women with BMI≥25 kg/m², high AMH level group showed an increased HOMA-IR when compared to normal AMH level. However, among PCOS women with normal BMI, women with high AMH presented an elevated fasting insulin levels but not HOMA-IR when compared to normal AMH group. In vitro treatment of isolated islet cells with high concentration of leptin (200 ng/ml) or high leptin plus high concentration of AMH (1 ng/ml) significantly enhanced insulin secretion. Importantly, co-treatment of AMH plus leptin upregulates the expression of pro-apoptotic proteins, such as Bax, caspase-3, and caspase-8 after incubating with a high level of glucose. These results suggest that AMH may involve in the pathological process of pancreatic β-cells in obese PCOS women.

Role of AMH in Prediction of Menopause

Anti-Müllerian Hormone (AMH) is produced by small antral follicles and has evolved over the past three decades as an assumed potential marker of the number of follicles in the human ovaries, also known as ovarian reserve. This quantitative measure, given the gradual decline over time and its non-replenishable feature, could be the dreamed marker for predicting the final exhaustion of ovarian storage: the post-menopause. This introductory chapter summarizes current knowledge with regard to the contribution of serum AMH measurements to predict age of normal menopause and critically discuss its potential in this regard. Furthermore, its predictive role in the context of menopause in association with several frequently occurring fertility disorders such as premature menopause, polycystic ovarian syndrome and endometriosis are discussed. Overall, while ovarian reserve markers including AMH are unmistakably related to age at menopause, they are insufficiently precise to inform on an individual's journey of ovarian aging.

Anti-Müllerian hormone (Amh/amh) plays dual roles in maintaining gonadal homeostasis and gametogenesis in zebrafish

Anti-Müllerian hormone (AMH/Amh) plays a role in gonadal differentiation and function across vertebrates. In zebrafish we demonstrated that Amh deficiency caused severe gonadal dysgenesis and dysfunction. The mutant gonads showed extreme hypertrophy with accumulation of early germ cells in both sexes, namely spermatogonia in the testis and primary growth oocytes in the ovary. In amh mutant females, the folliculogenesis was normal in young fish but receded progressively in adults, which was accompanied by progressive decrease in follicle-stimulating hormone (fshb) expression. Interestingly the expression of fshb increased in the pituitary of juvenile amh mutant males but decreased in adults. The upregulation of fshb in mutant male juveniles was likely one of the mechanisms for triggering gonadal hypergrowth, whereas the downregulation of fshb in adults might involve a negative feedback by gonadal inhibin. Further analysis using mutants of fshb and growth differentiation factor 9 (gdf9) provided evidence for a role of FSH in triggering ovarian hypertrophy in young female amh mutant as well. In summary, the present study provided comprehensive genetic evidence for dual roles of Amh in controlling zebrafish gonadal homeostasis and gametogenesis in both sexes. Amh suppresses proliferation or accumulation of early germ cells (spermatogonia in testis and primary growth oocytes in ovary) while promoting their exit to advanced stages, and its action may involve both endocrine and paracrine pathways.

Increased Body Mass Index Is Associated With A Nondilutional Reduction in Antimüllerian Hormone

CONTEXT

Controversy exists regarding if and how body mass index (BMI) impacts antimüllerian hormone (AMH) in women with and without polycystic ovary syndrome (PCOS). Understanding the BMI-AMH relationship has critical implications for clinical interpretation of laboratory values and could illuminate underlying ovarian physiology.

OBJECTIVE

To test the hypotheses that (1) BMI is associated with reduced AMH in PCOS and ovulatory controls (OVAs) and (2) the reduction in AMH is not accounted for by dilutional effects.

DESIGN/SETTING

Multicenter cohort.

PARTICIPANTS

Women aged 25 to 40 years from 2 clinical populations: 640 with PCOS, 921 women as OVAs.

MAIN OUTCOME MEASURES

Ovarian reserve indices: AMH, antral follicle count (AFC), and AMH to AFC ratio (AMH/AFC) as a marker of per-follicle AMH production.

RESULTS

In both cohorts, increasing BMI and waist circumference were associated with reductions in AMH and AMH/AFC, after adjusting for age, race, smoking, and site in multivariate regression models. Increasing BMI was associated with reduced AFC in PCOS but not OVAs. Body surface area (BSA), which unlike BMI is strongly proportional to plasma volume, was added to investigate a potential dilutive effect of body size on AMH concentrations. After controlling for BSA, BMI retained independent associations with AMH in both cohorts; BSA no longer associated with AMH.

CONCLUSIONS

In an adjusted analysis, BMI, but not BSA, was associated with reduced AMH; these data do not support a role for hemodilution in mediating the relationship between increased body size and reduced AMH. Decreased AMH production by the follicle unit may be responsible for reduced AMH with increasing BMI.

Endometriosis reduces ovarian response in controlled ovarian hyperstimulation independent of AMH, AFC, and women's age measured by follicular output rate (FORT) and number of oocytes retrieved

PURPOSE

To determine the influence of endometriosis on the ovarian response during controlled ovarian hyperstimulation measured by number of oocytes retrieved and the follicular output rate (FORT).

METHODS

A retrospective, single center study included 96 women, who underwent ICSI treatments for male factor infertility according to World Health Organisation between 2016 until 2018. A total of 96 patients were included in the study with 205 fresh ICSI cycles. The study group included 26 patients with endometriosis after surgical and medical treatment; the control group included 70 patients without endometriosis. The women with endometriosis underwent 47 and the control group 158 ICSI cycles. Women underwent fresh intracytoplasmatic sperm injection cycles after controlled ovarian hyperstimulation following a GnRH-antagonist protocol. The FORT was calculated as the ratio of pre-ovulatory follicle count × 100/small antral follicle count at baseline.

RESULTS

A lower number of retrieved oocytes (5.89 vs. 7.25, p = 0.045), lower FORT (75.67 vs. 94.63, p = 0.046), lower number of metaphase II oocytes (4.87 vs. 6.04, p = 0.046), and lower fertilization rate after intracytoplasmatic sperm injection (40.61 vs. 57.76, p = 0.003) were found in women with endometriosis compared to women without endometriosis. The number of oocyctes retrieved was 0.71 lower in the group with endometriosis than in the group without (p = 0.026). The FORT was 24.55% lower in the group with endometriosis (p = 0.025).

CONCLUSIONS

Endometriosis reduces the FORT and the number of metaphase-II oocytes after controlled ovarian hyperstimulation independly of women's age, antral follicle count and anti-Müllerian hormone.

Inferior fertility and higher concentrations of anti-Müllerian hormone in dairy cows with longer anogenital distance

Anogenital distance (AGD), which is an indicator of prenatal androgen exposure, has been reported to have high variability and negative association with fertility in dairy cows. Prenatal exposure to androgens could influence the development of primordial follicles and size of ovarian reserve, which is related to reproduction. However, the relationship between AGD and size of ovarian reserve has not been studied. Therefore, the present study was conducted to determine the association between AGD and circulating anti-Müllerian hormone (AMH), as an indirect marker of ovarian reserve, and to evaluate serum AMH concentration and reproductive performance in dairy cows with short and long AGD. Anogenital distance was measured 28 to 32 d postpartum, and based on the median of AGD, cows were divided into 2 subsets including short (n = 43) and long (n = 43) AGD groups. Afterward, serum AMH was evaluated on the day of estrus in cows that were estrus-synchronized. Furthermore, reproductive data of dairy cows during the previous lactation period were collected from the herd database. Concentrations of serum AMH tended to be positively associated with length of AGD, and there was a tendency for higher serum AMH concentrations in the long (634.89 ± 74.52 pg/mL) than short (451.39 ± 45.92 pg/mL) AGD group (0.05 <P ≤ 0.10). There was a tendency for more days to first service, lower first service conception rate, and higher proportion of repeat breeders in long (99.95 ± 5.34 d, 30.23% and 32.56%, respectively) than short (89.07 ± 4.97 d, 48.84% and 16.28%, respectively) AGD cows (0.05 <P ≤ 0.10). Services per conception did not differ between short (2.30 ± 0.27) and long (2.93 ± 0.29) AGD cows (P > 0.05). Calving to conception interval was prolonged in long (194.30 ± 17.12 d) than short (147.14 ± 13.11 d) AGD cows (P ≤ 0.05). In conclusion, the present study revealed elevated serum AMH concentrations and poor reproductive performance in cows with longer AGD compared with cows with shorter AGD.

Genome-wide association study of anti-Müllerian hormone levels in pre-menopausal women of late reproductive age and relationship with genetic determinants of reproductive lifespan

Anti-Müllerian hormone (AMH) is required for sexual differentiation in the fetus, and in adult females AMH is produced by growing ovarian follicles. Consequently, AMH levels are correlated with ovarian reserve, declining towards menopause when the oocyte pool is exhausted. A previous genome-wide association study identified three genetic variants in and around the AMH gene that explained 25% of variation in AMH levels in adolescent males but did not identify any genetic associations reaching genome-wide significance in adolescent females. To explore the role of genetic variation in determining AMH levels in women of late reproductive age, we carried out a genome-wide meta-analysis in 3344 pre-menopausal women from five cohorts (median age 44-48 years at blood draw). A single genetic variant, rs16991615, previously associated with age at menopause, reached genome-wide significance at P = 3.48 × 10-10, with a per allele difference in age-adjusted inverse normal AMH of 0.26 standard deviations (SD) (95% confidence interval (CI) [0.18,0.34]). We investigated whether genetic determinants of female reproductive lifespan were more generally associated with pre-menopausal AMH levels. Genetically-predicted age at menarche had no robust association but genetically-predicted age at menopause was associated with lower AMH levels by 0.18 SD (95% CI [0.14,0.21]) in age-adjusted inverse normal AMH per one-year earlier age at menopause. Our findings provide genetic support for the well-established use of AMH as a marker of ovarian reserve.

The role of anti-Müllerian hormone in prediction of pregnancy in young and older women with unexplained infertility undergoing intrauterine insemination

BACKGROUND

Serum anti-Müllerian hormone (AMH) level is considered to be a reliable marker of ovarian reserve. However, there are conflicting reports on the role of AMH level in predicting pregnancy after intrauterine insemination (IUI) cycles. The aim of this study is to investigate the clinical value of AMH in predicting pregnancy in younger and older women with unexplained infertility undergoing gonadotropin stimulation and IUI.

METHODS

The medical records of 84 women who underwent first gonadotropin-stimulated IUI cycle owing to unexplained infertility were retrospectively evaluated. The relation of AMH levels with clinical pregnancy rate was analyzed.

RESULTS

The overall clinical pregnancy rate was 19%. There was no significant difference in AMH levels between the pregnant and nonpregnant women (2.0 ± 1.0 vs 2.8 ± 2.0 ng/mL, respectively, p = 0.250). A further analysis according to age also failed to reveal significant differences in AMH levels between pregnant and nonpregnant women for both the younger (<35 years, n = 61) and the older (≥35 years, n = 23) subgroups (p = 0.714 and 0.532, respectively). Post-hoc power analysis showed a power of 0.80 with a 5% level of significance and a 0.8 effect size.

CONCLUSION

These findings indicate that AMH levels cannot predict pregnancy in women with unexplained infertility undergoing gonadotropin-stimulated IUI cycle. In addition, AMH is not a strong predictive factor for pregnancy either in younger or older women.

Current clinical applications of antimullerian hormone

PURPOSE OF REVIEW

Determine if literature supports the use of anti-Müllerian hormone (AMH) as a useful biomarker of reproductive potential when cumulative live birth rates (CLBRs) per retrieval are used as the outcome variable.

RECENT FINDINGS

Advances in technology used in in-vitro fertilization (IVF) permit the use of single embryo transfer to achieve expected pregnancy success rates. Many IVF cycles result in the creation of more than a single embryo suitable for transfer per oocyte retrieval. Cryopreservation permits subsequent use of other embryos with no loss in total reproductive potential from single retrievals. Therefore, an emerging concept in IVF is the CLBR per retrieval as an indicator of the patient's reproductive potential. Using the total reproductive potential from a single retrieval may help patients decide on IVF. As such, any predictor of success that relies upon the live birth rate for a single transfer, as opposed to CLBR per retrieval, is inadequate to estimate the true reproductive potential for patient. AMH has been proposed as a biomarker for reproductive potential, but most studies have correlated an AMH value to a single embryo transfer.

SUMMARY

A more appropriate way to use AMH levels may be to correlate the AMH with CLBR per retrieval. AMH may thus prove to be a useful biomarker when counseling patients about what to expect from their treatment.

The role of antimullerian hormone in assessing ovarian damage from chemotherapy, radiotherapy and surgery

PURPOSE OF REVIEW

Iatrogenic ovarian damage can occur after chemotherapy, radiotherapy and surgery for cancer as well as for non-malignant conditions. This review describes the effects of such treatment on antimullerian hormone (AMH) and the implications of the fall in AMH in relation to ovarian function and fertility, especially in the era of improved fertility preservation strategies.

RECENT FINDINGS

The risk of gonadotoxicity differs between chemotherapy regimens. There is growing evidence that pretreatment AMH has prognostic significance for the degree of fall in AMH after treatment, the reversibility of ovarian damage and risk of premature ovarian insufficiency. The accuracy of prediction increases when age is coupled with AMH. The adverse effect of removal of endometriomas is increasingly clear, and AMH pre and post surgery useful is assessing the degree of damage to the ovary. The implications of low AMH after such treatment on natural fertility and reproductive lifespan are less clear. Apart from treatment effects, there are other coexisting conditions that can affect AMH which needs to be taken into consideration during interpretation of AMH before and after treatment.

SUMMARY

A fall in AMH in women after gonadotoxic treatment has been consistently described, with variable recovery, the accurate interpretation and clinical application of post-treatment AMH level on reproductive lifespan and fertility prediction needs to be studied in future larger prospective studies with longer follow-up.

Müllerian inhibiting substance/anti-Müllerian hormone as a fertility preservation agent

PURPOSE OF REVIEW

The nascent field of oncofertility is quickly gaining traction as novel experimental treatments are being developed, driving a renewed interest in Müllerian inhibiting substance (MIS) as an ovarian fertoprotectant.

RECENT FINDINGS

MIS is unique in its mechanisms of ovarian protection by virtue of acting directly on granulosa cells of primordial follicles and for being a benign reproductive hormone, with few side effects. We will explore in this review how it may be utilized to protect the ovary from chemotherapy, or to enhance ovarian tissue cryopreservation therapy. We will also examine potential mechanisms of action of MIS across multiple cell types, as well as current limitations in our understanding of the pharmacology of recombinant MIS.

SUMMARY

The usefulness of MIS as a fertoprotectant may be dependent on the mechanisms of gonadotoxicity of each chemotherapeutic. Further investigation is needed to determine how to best deliver and combine MIS treatment to existing fertility management strategies.

Anti-Müllerian hormone as a predictor of reproductive potential

PURPOSE OF REVIEW

Anti-Müllerian hormone (AMH), a marker of ovarian reserve, declines over a woman's reproductive lifespan. AMH is highly correlated with a woman's age and number of primordial ovarian follicles, and has been shown to predict time to menopause in women in their 40s. For these reasons, it was assumed that AMH levels could predict a woman's reproductive potential or serve as a 'fertility test'. Recently, studies have sought to determine the association between AMH and fertility.

RECENT FINDINGS

Although a small, prospective, time-to-pregnancy study of 98 women suggested that an AMH level less than 0.7 ng/ml was associated with lower day-specific probabilities of conception, the follow-up, larger cohort did not identify an association with AMH and fecundability. Women with AMH values less than 0.7 ng/ml had similar pregnancy rates after 12 cycles of attempting to conceive as women with normal AMH values after adjusting for age. Four additional studies, including a secondary analysis of the NICHD EAGER trial including over 1200 women confirmed these findings.

SUMMARY

Although AMH is a marker of ovarian reserve, existing literature does not support the use of AMH as a marker of reproductive potential in the general population.

Anti-müllerian hormone in the pathophysiology and diagnosis of polycystic ovarian syndrome

PURPOSE OF REVIEW

Polycystic ovarian syndrome (PCOS) is the most common cause of chronic anovulation and hyperandrogenism in young women and represents a true public health concern and an economic burden.

RECENT FINDINGS

The pathophysiology of PCOS is still not fully understood, but progresses have been made and the relationships between anti mullerian hormone (AMH), follicle stimulating hormone, luteinizing hormone, E2 and androgens have been explored. The follicle excess plays a central role in the syndrome and AMH is definitively a major component of this phenomena.

SUMMARY

The aim of this chapter is to present the recent work studying the role of AMH in the pathophysiology of PCOS and to discuss the improvement that serum AMH assay brings in the diagnosis of PCOS.

Relationship between anti-Müllerian hormone and fertility in the mare

The objectives of this study were to evaluate; 1) the stability of measured serum anti-Müllerian hormone (AMH) concentrations in samples after multiple freeze-thaw cycles, 2) the repeatability of AMH concentrations within mares during the same breeding season as well as across breeding seasons, and 3) the relationship between serum AMH concentrations and fertility (measured as first cycle pregnancy rates) in thoroughbred mares. For the first aim, AMH concentrations (n = 9) were examined across four freeze-thaw cycles with no significant change in measured AMH concentrations. For the second aim, serum AMH concentrations (n = 12) were examined over three successive estrous cycles and over two successive breeding seasons and AMH levels were significantly correlated for individual animals within (r; 0.71-82) or across breeding seasons (r = 0.81). For the third aim, Thoroughbred mares (n = 419) on farms in central Kentucky had blood samples taken during estrus. Pregnancy was determined with transrectal ultrasonography at Days 13-18 after mating and ovulation, and pregnancy outcome was recorded as open, pregnant or twins. The relationships between mare age, serum AMH concentrations and the interaction of age and AMH with pregnancy outcome was examined by nominal logistic regression, and the relationship between serum AMH concentrations and mare age, pregnancy outcome and the interaction of age and pregnancy outcome was examined by ANOVA. Data in this study were then stratified according to quartiles into lower (25%), mid-50% (second and third quartiles combined - 50%) and upper (25%) quartiles for age and serum AMH concentration for further analysis by logistic regression. There were significant effects of mare age and pregnancy outcome, but not their interaction on serum AMH concentrations which were higher (P = 0.04) in pregnant than in open mares (0.65 ± 0.03 vs 0.55 ± 0.04 ng/mL, respectively). Likewise, logistic regression revealed significant effect of mare age and AMH but not their interaction on pregnancy outcome on the first mated cycle. Mares in the lower AMH quartile were more likely to be open at Day 13-18 than mares in the middle (odds ratio (OR) = 1.87)=13 or upper quartile (OR = 2.62) for AMH concentrations. Mares in the mid-50% (OR = 3.91) or upper (OR = 4.97) age quartile were more likely to be open at Day 13-18 compared to mares in the young age quartile. Based upon a Chi-squared analysis, the proportion of pregnant mares differed across age quartiles (P < 0.0001) and was greater (P < 0.05) in the young mare quartile. The proportion of pregnant mares tended to differ across AMH quartile (P = 0.1), and when adjusted for age quartile using the Cochran-Mantel-Haenszel Test, the proportion of pregnant mares differed (P < 0.05) across AMH quartile. In conclusion, mares with peripheral AMH concentrations in the lowest quartile had lower fertility compared to mares in the mid-50% or upper quartile.

Anti-Müllerian hormone overexpression restricts preantral ovarian follicle survival

Anti-Müllerian hormone (AMH) is an ovarian regulator that affects folliculogenesis. AMH inhibits the developmental activation of the dormant primordial follicles and the oocyte within. In more mature follicles, AMH reduces granulosa cell sensitivity to follicle-stimulating hormone (FSH). We examined the effects of AMH overexpression on the stages of ovarian folliculogenesis, and the development of embryos, with a transgenic mouse that overexpresses human AMH in central nervous system neurons under the control of the mouse Thy1.2 promoter (Thy1.2-AMH^Tg mice). These mice are severely sub-fertile, despite relatively normal ovulation rates. The embryos of Thy1.2-AMH^Tg females exhibited delayed preimplantation development and extensive mid-gestation fetal resorption. Young Thy1.2-AMH^Tg mouse ovaries exhibited only a slight reduction in the rate of primordial follicle activation but large declines in the number of developing follicles surviving past the primary stage. It was expected that Thy1.2-AMH^Tg mice would retain more primordial follicles as they aged, but at 5 months, their number was significantly reduced relative to wild-type females. These data indicate that moderate elevations in AMH levels can severely restrict reproductive output and the number of developing follicles in the ovary. This evidence suggests that early antral follicles are a target for AMH signaling, which may regulate early follicle survival.

Circulating anti-Müllerian hormone (AMH) associates with the maturity of boys' drawings: Does AMH slow cognitive development in males?

PURPOSE

High levels of circulating anti-Müllerian hormone are unique to developing males, but the function of anti-Müllerian hormone in boys is unknown. In mice, anti-Müllerian hormone contributes to the male biases in the brain, but its receptors are present throughout non-sexually dimorphic portions of the brain. In humans, the speed of maturation is the most overt difference between girls and boys. We postulate that this is because anti-Müllerian hormone slows the maturation of the male human brain.

METHODS

One hundred and fourty three 5-year or 6-year-old boys and 38 age-matched girls drew a person and donated a blood sample. The children's drawings were blind-scored to generate a maturity index. The level of anti-Müllerian hormone and the other Sertoli cell hormone, inhibin B, were measured by ELISA. The relationship between the children's age, hormones and maturity index were examined by linear regression analysis.

RESULTS

The girls drew more complex and realistic person than the boys (32%, p = 0.001), with their drawings also being larger (39%, p = 0.037) and more coloured-in (235%, p = 0.0005). The maturity index in boys correlated with age (+r = 0.43, p < 0.0005) and anti-Müllerian hormone level (-r = -0.29, p < 0.0005). The association between maturity index and anti-Müllerian hormone level persisted when corrected for age and for inhibin B (r = -0.24, p = 0.0005). The calculated effect of the median level of anti-Müllerian hormone (1 nM) was equal to 0.81 months of development. The size and colouring of the drawings did not correlate with the boys' age, anti-Müllerian hormone or inhibin B.

CONCLUSIONS

This exploratory study provides the first indicative evidence that circulating anti-Müllerian hormone may influence the development of the human brain.

Polycystic ovary syndrome in adolescent girls

PURPOSE OF REVIEW

Polycystic ovary syndrome (PCOS) is a common heterogeneous disorder that appears to have its origins during the peripubertal years. The diagnostic conundrum is that the typical clinical features, irregular menses and acne, occur during normal female puberty. Understanding the physiologic origins and molecular basis of the dysregulated hypothalamic-pituitary-gonadal axis in PCOS is fundamental to interrupting the distinctive vicious cycle of hyperandrogenism and chronic anovulation.

RECENT FINDINGS

Newer ultrasound technology with better spatial resolution has generated controversy regarding the optimal imaging criteria to define polycystic ovary morphology. Using such equipment, the Androgen Excess PCOS Society Task Force Report recommends a threshold of at least 25 follicles per ovary as the definition of polycystic ovary morphology. The implementation and results of genome-wide association studies has opened a new window into the pathogenesis of PCOS. Recent genome-wide association studies have identified several loci near genes involved in gonadotropin secretion, ovarian function, and metabolism. Despite the impediments posed by phenotypic and genetic heterogeneity among women with PCOS, investigation into one locus, the DENND1A gene, is providing insight into the ovarian steroidogenesis. Anti-Mullerian hormone (AMH) has long been recognized to play a major role in the ovarian dysfunction. Recent animal data implicate AMH in the neuroendocrine dysregulation by demonstrating AMH-stimulated increased gonadotropin releasing hormone and luteinizing hormone secretion.

SUMMARY

PCOS is a common complex multifaceted disorder associated with genetic and environmental influences affecting steroidogenesis, steroid metabolism, neuroendocrine function, insulin sensitivity, pancreatic β cell function, and alternative adaptations to energy excess. Current research into the genetics and pathophysiology is reviewed. The difficulties inherent in diagnosing PCOS in adolescent girls are discussed.

Role of Anti-Müllerian Hormone in pathophysiology, diagnosis and treatment of Polycystic Ovary Syndrome: a review

Polycystic ovary syndrome (PCOS) is the most common cause of chronic anovulation and hyperandrogenism in young women. Excessive ovarian production of Anti-Müllerian Hormone, secreted by growing follicles in excess, is now considered as an important feature of PCOS. The aim of this review is first to update the current knowledge about the role of AMH in the pathophysiology of PCOS. Then, this review will discuss the improvement that serum AMH assay brings in the diagnosis of PCOS. Last, this review will explain the utility of serum AMH assay in the management of infertility in women with PCOS and its utility as a marker of treatment efficiency on PCOS symptoms. It must be emphasized however that the lack of an international standard for the serum AMH assay, mainly because of technical issues, makes it difficult to define consensual thresholds, and thus impairs the widespread use of this new ovarian marker. Hopefully, this should soon improve.

[Anti-Müllerian hormone is a clinical useful measure of the ovarian reserve]

Anti-Müllerian hormone (AMH) is produced by the growing follicles in the ovaries. The number of follicles in this pool is proportional to the number of primordial follicles in the resting pool (the "ovarian reserve"), thus AMH is believed to be a surrogate marker of the ovarian reserve. AMH is a useful adjunct in the evaluation of a woman's "reproductive age", being an important parameter in counselling for reproduction. AMH is also used in pretreatment evaluation of infertile patients guiding proper hormone stimulation. Furthermore, AMH can be used as a tumour marker for granulose cell tumours.

Determination of anti-Müllerian hormone at estrus during a synchronized and a natural bovine estrous cycle

Anti-Müllerian hormone (AMH) has been correlated with phenotypic indicators of fertility. However, the effects of exogenous hormones used during estrus synchronization on AMH have not been evaluated. Therefore, the objective of this experiment was to determine whether concentrations of AMH at estrus are similar between a synchronized compared with a natural estrous cycle. Nulliparous dairy and beef heifers (n = 68) were synchronized with the Select Synch + controlled internal drug release (CIDR) protocol (GnRH + CIDR-7 d-CIDR removal + PG). Heifers were observed for expression of estrus every 6 h until 84 h after the injection of PG. Visual detection of the subsequent estrus, considered natural estrus, occurred every 6 h from day 16 to 24 after synchronized estrus. At the time of standing estrus, ovarian structures in heifers were evaluated by transrectal ultrasonography. Blood samples were collected at estrus for analysis of concentrations of AMH during the synchronized and natural estrous cycles. The GLM and CORR procedures of SAS were used to analyze data. Concentrations of AMH between natural and synchronized estrus were positively correlated (r = 0.67; P < 0.001). Mean concentration of AMH did not differ (P > 0.05) between the natural (0.0543 ± 0.0076 ng/mL) or synchronized (0.0428 ± 0.0076 ng/mL) estrous cycles. In conclusion, concentrations of AMH were similar between natural and synchronized estrous cycles. Concentrations of AMH in natural and synchronized estrous cycles were highly correlated within individual heifers and varied among heifers with beef heifers having increased (P < 0.05) concentrations of AMH compared with dairy heifers (0.0638 ± 0.01 and 0.0402 ± 0.01 ng/mL, respectively).

The bed nucleus of the stria terminalis has developmental and adult forms in mice, with the male bias in the developmental form being dependent on testicular AMH

Canonically, the sexual dimorphism in the brain develops perinatally, with adult sexuality emerging due to the activating effects of pubescent sexual hormones. This concept does not readily explain why children have a gender identity and exhibit sex-stereotypic behaviours. These phenomena could be explained if some aspects of the sexual brain networks have childhood forms, which are transformed at puberty to generate adult sexuality. The bed nucleus of stria terminalis (BNST) is a dimorphic nucleus that is sex-reversed in transsexuals but not homosexuals. We report here that the principal nucleus of the BNST (BNSTp) of mice has developmental and adult forms that are differentially regulated. In 20-day-old prepubescent mice, the male bias in the principal nucleus of the BNST (BNSTp) was moderate (360 ± 6 vs 288 ± 12 calbindin(+ve) neurons, p < 0.0001), and absent in mice that lacked a gonadal hormone, AMH. After 20 days, the number of BNSTp neurons increased in the male mice by 25% (p < 0.0001) and decreased in female mice by 15% (p = 0.0012), independent of AMH. Adult male AMH-deficient mice had a normal preference for sniffing female pheromones (soiled bedding), but exhibited a relative disinterest in both male and female pheromones. This suggests that male mice require AMH to undergo normal social development. The reported observations provide a rationale for examining AMH levels in children with gender identity disorders and disorders of socialization that involve a male bias.

Is AMH useful to reduce low ovarian response to GnRH antagonist protocol in oocyte donors?

We aimed to establish the reference values of Anti-Müllerian hormone (AMH) in our oocyte donor population and correlate them with the ovarian response to an antagonist stimulation protocol and to study the predictive capacity of AMH for poor response (PR). Normal AMH curves were obtained for 172 candidates. AMH levels decreased with age although they showed great heterogeneity and spread in absolute values at any age range. AMH levels showed a positive correlation, statistically significant, with the Antral Follicle Count (r = 0,705), and number of oocytes retrieved (r = 0,356). In receiver operating characteristic curve analysis a threshold value of AMH = 2.31 ng/ml predictive for retrieval <6 MII (area under the curve (AUC) 0.675) was identified. This cut-off predicted PR with a sensitivity of 70.4% and a specificity of 61.8%, (PPV = 39.6%; NPV = 85.5%, p = 0.004). When performing a multiple logistic regression analysis including age, AFC and FSH, an AUC = 0.668 for PR was obtained whereas if AMH was added to the model it resulted in an AUC = 0.713. In oocyte donors aged 18 to 35 with an AFC ≥ 10 and basal FSH <10 mIU/ml, measuring AMH levels improved just slightly the prediction for PR.

Disordered follicle development

Alterations of ovarian follicle morphology and function have been well documented in women with PCOS. These include increased numbers of growing preantral follicles, failure of follicle growth beyond the mid-antral stage, evidence of granulosa call degeneration, and theca cell hyperplasia. Functional abnormalities include paradoxical granulosa cell hyperresponsiveness to FSH which is clinically linked to ovarian hyperstimulation during ovulation induction. In addition, there is likely a primary theca cell defect that accounts for the majority of excess androgen production in this disorder. The precise mechanisms responsible for altered follicle function are not completely clear. However, several factors appear to influence normal advancement of follicle development as well as impair ovarian steroidogenesis. These include intra- as well as extraovarian influences that distort normal ovarian growth and disrupt steroid production by follicle cells.

Common pathophysiological mechanisms involved in luteal phase deficiency and polycystic ovary syndrome. Impact on fertility

Luteal phase deficiency (LPD) is a consequence of the corpus luteum (CL) inability to produce and preserve adequate levels of progesterone. This is clinically manifested by short menstrual cycles and infertility. Abnormal follicular development, defects in neo-angiogenesis or inadequate steroidogenesis in the lutein cells of the CL have been implicated in CL dysfunction and LPD. LPD and polycystic ovary syndrome (PCOS) are independent disorders sharing common pathophysiological profiles. Factors such as hyperinsulinemia, AMH excess, and defects in angiogenesis of CL are at the origin of both LPD and PCOS. In PCOS ovulatory cycles, infertility could result from dysfunctional CL. The aim of this review was to investigate common mechanisms of infertility in CL dysfunction and PCOS.

Analysis of androgen receptor and anti-Müllerian hormone pathways in human granulosa cells under luteinizing hormone treatment

BACKGROUND

The objective of this study was to determine the gene expression profiles of the androgen/androgen receptor (AR) and anti-Müllerian hormone (AMH)/ Sry-related high-mobility group box 9 (SOX9) pathways in granulosa-luteal cells from patients undergoing standard in vitro fertilization (IVF) with or without recombinant luteinizing hormone (rLH) therapy.

METHODS

Levels of reproductive hormones in the pre-ovulatory follicular fluid and the expression levels of LHR (luteinizing hormone receptor), AR, SOX9, AMH, AR-associated protein 54(ARA54)and ARA70 were determined in granulosa-luteal cells by real-time reverse-transcription PCR. The effects of androgen and rLH treatments on AR and AMH expression levels were also tested in vitro using HO23 cells.

RESULTS

We collected 35 an 70 granulosa cell samples from patients cycled with and without rLH supplementation, respectively. The clinical outcomes were similar in patients who received rLH therapy and those who did not, though the pre-ovulatory follicular fluid levels of androstenedione, testosterone, and estradiol were significantly higher and progesterone was lower in the rLH supplementation group. Moreover, granulosa-luteal cell mRNA levels of LHR, AR, AMH, and SOX9 were significantly higher in the rLH supplementation group relative to the group that did not receive rLH supplementation. In addition, we observed significant correlations between LHR and AR mRNA expression and among AR, AMH, and SOX9 mRNA expression in granulosa-luteal cells from patients undergoing standard IVF treatment.

CONCLUSIONS

Increased expression of LHR, AR, AMH, and SOX9 is characteristic of granulosa-luteal cells from IVF/ intracytoplasmic sperm injection (ICSI) patients receiving rLH supplementation.

The practical role of anti-Müllerian hormone in assisted reproduction

The objective of this study was to offer a brief critical summary of the literature on the role of AMH in the subfertility work up and during ART, while exploring its role in predicting ART success.

Infertility: definitions and strategies

Anti-Müllerian hormone is a sensitive marker of ovarian reserve and is suitable for screening. This is important for all women whose age is not critical yet and who not started their "project of family planning". Looking up individual anti-Müllerian hormone levels in percentile normograms inform about the biological clock which might be put back or forward. By this anti-Müllerian hormone supports clinical decisions.

Anti-Müllerian hormone: an ovarian reserve marker in primary ovarian insufficiency

Primary ovarian insufficiency (POI), also known as premature ovarian failure, is a disorder of infertility characterized by amenorrhoea, low estrogen levels and increased gonadotropin levels in women aged <40 years. POI is the result of premature exhaustion of the follicle pool or can be attributed to follicular dysfunction, for example, owing to mutations in the follicle-stimulating hormone receptor or steroidogenic cell autoimmunity. Moreover, advances in cancer therapeutics over the past decades have led to increasing survival rates for both paediatric and adult malignancies. Given the gonadotoxic effect of many cancer treatments, more women develop POI. A marker that predicts whether women are at risk of POI would, therefore, aid in early diagnosis and fertility counselling. Anti-Müllerian hormone (AMH), a growth factor produced solely by small, growing follicles in the ovary, might constitute such a marker, as serum levels of this hormone correlate strongly with the number of growing follicles. In addition, AMH could potentially help assess the progression of ovarian senescence, as serum AMH levels are independent of hypothalamic-pituitary-gonadal axis function and decrease to undetectable levels at menopause. In cancer survivors, serum AMH levels correlate with the extent of gonadal damage. In this Review, we provide an overview of the current studies that have measured AMH in women with POI of various aetiologies and discuss its possible application as a marker to determine ovarian reserve.

Anti-Mullerian hormone confirms the novel classification of female functional androgenization including polycystic ovary syndrome

OBJECTIVE

Functional androgenization (FA) can be divided into five groups corresponding to the predominant organ pathology as recently shown by our group: functional cutaneous androgenization (FCA, skin) and FA syndrome (FAS) I (ovary, lean individual), II (adrenal gland), III (ovary, fat tissue, pancreas, and hyperinsulinemia), and IV (residual FA dysfunctions). Group-specific clusters are based on primary variables such as LH, testosterone, DHEAS, sex hormone-binding globulin (SHBG), body mass index (BMI), glucose, insulin, and enlarged polyfollicular ovaries. Because anti-Müllerian hormone (AMH) positively correlates with the antral follicle count, its relevance as an additional primary variable for classifying FA was investigated.

DESIGN

In this study, 178 patients with FA were consecutively enrolled and classified into the five FA groups as described earlier and 30 women with regular menstrual cycles served as control.

METHODS

Primary variables and serum AMH were analyzed in the early follicular phase.

RESULTS

FA patients showed significantly elevated AMH levels (11.1±6.7 ng/ml) versus control (3.0±2.0 ng/ml; P<.0001). AMH was significantly increased in groups FAS I (15.6±5.8 ng/ml) and FAS III (11.6±6.6 ng/ml) compared with groups FCA (7.0±3.8 ng/ml), FAS II (5.05±3.0 ng/ml), and FAS IV (6.9±4.6 ng/ml) and correlated positively (P<.0001) with LH (r=0.538) and testosterone (r=0.368). In regression and multivariate analyses, AMH was not dependent on SHBG, DHEAS, BMI, glucose, or insulin. In receiver operating characteristic analysis, 9.21 ng/ml AMH showed 90% specificity with 71.2% sensitivity for the diagnosis of the two ovarian FA groups, FAS I and III.

CONCLUSION

AMH confirms the novel stratification system and constitutes a useful primary variable in the algorithm of FA classification.

Normal male sexual differentiation and aetiology of disorders of sex development

Fetal sex development consists of three sequential stages: a) the undifferentiated stage, when identical primitive structures develop in the XY and XX embryos, b) gonadal differentiation into testes or ovaries, and c) the differentiation of internal and external genitalia, which depends on the action of testicular hormones. Disorders of sex development (DSD) may result from defects in any of these stages. Abnormal formation of the anlagen of internal and/or external genitalia in early embryonic development results in Malformative DSD. In patients with a Y chromosome, defects in testis differentiation drive to early-onset fetal hypogonadism affecting whole testicular function, a condition named Dysgenetic DSD. In Non-dysgenetic DSD, the underlying pathogenesis may involve early-onset fetal hypogonadism affecting specifically either Leydig or Sertoli cell function, or male hormone end-organ defects in patients devoid of fetal hypogonadism. Understanding the pathogenesis is useful for an efficient early diagnosis approach, which is necessary for adequate decision making in the management of DSD.

Mechanisms of follicle selection and development

Follicle recruitment and selection, the process that gives rise to the dominant follicle (DF) and the physiological state of the DF are important areas of research. The selection of a single ovarian follicle for further differentiation and finally ovulation is a shared phenomenon in monovulatory species including humans. The DF is different from other follicles because it can escape atresia (the fate of all other follicles). The DF cells develop corpus luteum if exposed to the luteinizing hormone (LH) surge. Several mechanisms for DF selection have been proposed. Rising follicle stimulating hormone (FSH) concentrations induce the emergence of a follicle wave and cohort attrition occurs during declining FSH concentrations, resulting in DF selection. Cohort secretions are initially responsible for the decline in FSH, which is subsequently suppressed by the selected DF lowering it below the threshold of FSH requirements of all other cohort follicles. The DF acquires relative FSH-independence in order to continue growth and differentiation during further declining FSH concentrations. A transition from FSH- to LH-dependence is postulated as the mechanism for the continued development of the selected DF. In addition, FSH and insulin-like-growth factor (IGF) enhance each other's ability to stimulate follicle cell function. Access of IGF II to their receptors is regulated by IGF binding proteins that are in turn regulated by specific proteases; all of which have been ascribed a role in DF development. One other shared mechanism recently proposed for DF selection is the possible differential regulation of blood vessel formation. Anti-Müllerian hormone (AMH) also plays a critical role in selection of the DF. AMH levels decline as the size of the follicle increases. Once follicles reach a size at which they are dominant, it has largely disappeared. From the time a follicle has been selected, the follicle destined to ovulate greatly enlarges and shows marked changes in its steroidogenic activity. LH surge causes a significant decline in gap junctions leading to dissociation of mural granulosa cells (GC) and expansion of the cumulus-oocyte complex (COC). The oocyte resumes its meiosis and progresses from prophase 1 to metaphase 2 at the time of ovulation. The concept of DF selection could be applied to the in-vitro maturation (IVM) program. Understanding the mechanism of DF selection in menstrual cycles is the key to planning the optimal timing of oocyte retrieval in order to obtain competent oocytes and embryos. Although the timing of oocyte retrieval is still open to debate, there is evidence to suggest that it may be better to retrieve oocytes before the small cohort follicles complete the process of atresia following selection of the DF.

Serum anti-Müllerian hormone levels are negatively related to Follicular Output RaTe (FORT) in normo-cycling women undergoing controlled ovarian hyperstimulation

BACKGROUND

Since in rodents anti-Müllerian hormone (AMH) has been shown to inhibit antral follicle responsiveness to FSH, we aimed at verifying whether a relationship exists between serum AMH levels and antral follicle responsiveness to exogenous FSH in normo-cycling women.

METHODS

Serum AMH, estradiol (E(2)) and FSH levels were prospectively measured on cycle day 3 in patients undergoing controlled ovarian hyperstimulation (COH) with a time-release GnRH agonist and standardized FSH doses. In 162 patients, follicles were counted after pituitary suppression and before FSH administration (baseline; small antral follicles; 3-8 mm), and on the day of hCG (dhCG; pre-ovulatory follicles; 16-22 mm). Antral follicle responsiveness to FSH was estimated by the Follicular Output RaTe (FORT), determined by the ratio pre-ovulatory follicle count on dhCG × 100/small antral follicle count at baseline.

RESULTS

Serum AMH levels were positively correlated with the number of small antral follicles at baseline (r = 0.59; P < 0.0001) and pre-ovulatory follicles on dhCG (r = 0.17; P < 0.04). Overall, FORT was 47.5 ± 1.4% and failed to be influenced by the woman's age, BMI or basal E(2) and FSH level. Conversely, multiple regression analysis showed that FORT was negatively correlated with AMH levels (r = -0.30; P < 0.001), irrespective of duration of COH and total FSH dose.

CONCLUSIONS

The percentage of follicles that effectively respond to FSH by reaching pre-ovulatory maturation is negatively and independently related to serum AMH levels. Although the mechanisms underlying this finding remain unclear, it is in keeping with the hypothesis that AMH inhibits follicle sensitivity to FSH.

Serum levels of antimüllerian hormone in women with regular menstrual cycles

Antimüllerian hormone (AMH) is produced by Sertolli cells of the testes and granulosa cells of the ovaries. Recent studies have indicated that AMH may be a novel measure of ovarian reserve. Also, earlier reports have presented minimal fluctuations ofAMH levels throughout the menstrual cycle. The aim of this preliminary study was to demonstrate the relation of serum AMH levels and age in women with regular menstrual cycles and normal hormonal regulation of ovarian function. The study included 35 women divided into two groups of women aged 30 or younger and those older than 30. Hormone concentrations were assessed by measurements of lutropin (LH), follitropin (FSH), estradiol (E2), testosterone (T), sex hormone binding globulin (SHBG) and AMH on cycle day 3-5 (follicular phase); and LH, FSH and E2 on cycle day 13-15 (ovulation). Progesterone level was determined on cycle day 19-23 (luteal phase). Median age differed significantly between the two groups of study subjects (P = 0.001). Study results confirmed regular ovarian response to physiological gonadotropin stimulation, which is the assumption for normo-ovulatory cycles. Some decrease in the mean serum AMH levels was recorded in women over 30 years of age, although the difference was not statistically significant (P = 0.0693). There was no statistically significant difference in serum AMH concentrations between follicular phase and ovulation in study women (P = 0.3124). Our preliminary results, although obtained in a limited number of women, support the diagnostic value of AMH as a reliable marker of ovarian reserve.

Control of sex development

The process of sexual differentiation is central for reproduction of almost all metazoan, and therefore, for maintenance of practically all multicellular organisms. In sex development, we can distinguish two different processes, sex determination, that is the developmental decision that directs the undifferentiated embryo into a sexually dimorphic individual. In mammals, sex determination equals gonadal development. The second process known as sex differentiation takes place once the sex determination decision has been made through factors produced by the gonads that determine the development of the phenotypic sex. Most of the knowledge on the factors involved in sexual development came from animal models and from studies of cases in whom the genetic or the gonadal sex does not match the phenotypical sex, that is, patients affected by disorders of sex development (DSDs). Generally speaking, factors influencing sex determination are transcriptional regulators, whereas factors important for sex differentiation are secreted hormones and their receptors. This review focuses on these factors and whenever possible, references regarding the 'prismatic' clinical cases are given.

Repetitive oocyte donation does not decrease serum anti-Müllerian hormone levels

OBJECTIVE

To determine if the anti-Müllerian hormone (AMH), a proposed marker of ovarian aging, decreases with repetitive oocyte donation.

DESIGN

Retrospective cohort.

SETTING

Academic.

PATIENT(S)

Thirty-six young women who underwent three to seven oocyte donation cycles.

INTERVENTION(S)

Assessor blind determination of AMH levels from serum samples collected during each treatment cycle.

MAIN OUTCOME MEASURE(S)

Cycle trends of serum AMH levels.

RESULT(S)

The AMH was the only predictor of oocyte yield in the first cycles. The AMH was negatively associated with donor age and follicle stimulating hormone (FSH) dose used. Serum AMH levels did not show any decrease per treatment cycle basis and per maximum number of oocyte donation cycles performed per woman. Whereas donors who underwent six cycles showed increasing AMH levels when controlled for studied covariates, the slopes of the multiple regression curves were not significantly different from donors who underwent three, four, and five cycles. Clinical outcome assessed by FSH dose/number of oocytes ratio did not show significant change over repetitive cycles. Intercycle variation of AMH in all patients over three cycles was found to be 12.5%, which was within the reported intermenstrual range.

CONCLUSION(S)

Serum AMH levels do not decrease over repetitive oocyte donation cycles, which may imply that accelerated ovarian aging may not occur in oocyte donors.

Intra-follicular regulatory mechanisms in the porcine ovary

The mechanisms controlling the follicular growth continuum in the pig involve the interaction between local growth factors which are expressed throughout development and extra-follicular factors such as gonadotrophins. A large number of follicular growth factors, many belonging to the transforming growth factor-beta (TGF-beta) superfamily, have been identified in the somatic cells and in the oocyte. The relative importance of these intra-follicular factors varies with stage of development. The initiation of follicular growth and early preantral development is controlled locally (by factors including c-kit-kit ligand, members of the bone morphogenetic family (e.g BMP-15) and growth differentiation factor-9 (GDF-9)) and gonadotrophins are not thought to be involved until later. During antral follicle development, the oocyte secretes factors that stimulate porcine granulosa cell proliferation and differentiation, modulate apoptosis and suppress progesterone production, thereby preventing premature luteinisation. Likely candidates for mediating these effects include BMP-6, -15 and GDF-9 that are critical for fertility and ovulation rate in several mammals. There are also paracrine interactions between the somatic cells, with theca derived transforming growth factor beta (TGF-beta) playing a key role in regulating antral follicle maturation. Finally, during the periovulatory period, members of the EGF family from the granulosa cells stimulate cumulus expansion and oocyte maturation. Evidence indicates that some of these local factors may also influence oocyte developmental potential, emphasizing further the complexity, and importance, of these intra-follicular interactions.

Polycystic ovary syndrome: pathophysiology, molecular aspects and clinical implications

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age (5-10% prevalence) and the most common cause of anovulatory infertility. A recent consensus has led to the formulation of unifying diagnostic criteria for PCOS. It is multifactorial and polygenic in nature. Although the ovary is central to the pathogenesis of PCOS, however neuroendocrine, ovarian and metabolic dysfunctions play a significant role in the pathophysiology. Short- and long-term consequences of the syndrome have been the focus of much interest. The association of PCOS with hyperandrogenism, hyperinsulinemia and insulin resistance is known and some of the putative molecular aspects are established. Menstrual abnormalities (oligo- or amenorrhea), subfertility, obesity and symptoms of androgen excess are often the main reasons for early referral, whereas diabetes, cardiovascular disease and endometrial cancer represent a clinical finding later in life. It is plausible that appropriate specialist medical management improves the wellbeing of women with PCOS.

Physiological androgen insensitivity of the fetal, neonatal, and early infantile testis is explained by the ontogeny of the androgen receptor expression in Sertoli cells

CONTEXT

Although gonadotropins and testosterone are high in the fetal/early postnatal periods, Sertoli cells remain immature and spermatogenesis does not progress. We hypothesized that Sertoli cells do not respond to testosterone because they do not express the androgen receptor.

OBJECTIVE

The objective of the study was to describe the precise ontogeny of androgen receptor expression in the human testis from fetal life through adulthood.

DESIGN

This was an immunohistochemical study on testicular biopsies from fetal, neonatal, prepubertal, pubertal, and adult human testes.

MAIN OUTCOME MEASURES

Quantification of androgen receptor expression in Sertoli cells was measured. Evaluation of androgen receptor expression in peritubular and interstitial cells as well as anti-Müllerian hormone and inhibin-alpha was also performed.

RESULTS

Androgen receptor expression was first observed in the nuclei of few Sertoli cells at the age of 5 months. Labeling was weak in 2-15% of Sertoli cells until 4 yr of age and progressively increased thereafter. High levels of androgen receptor expression were observed in more than 90% from the age of 8 yr through adulthood. Androgen receptor was positive in peritubular cells and variable in interstitial cells. Anti-Müllerian hormone immunolabeling was strong in all Sertoli cells from fetal life throughout prepuberty and weakened progressively as spermatogenesis developed. Inhibin-alpha expression was detected in all Sertoli cells from fetal life through adulthood.

CONCLUSIONS

A lack of androgen receptor expression could explain a physiological Sertoli cell androgen insensitivity during fetal and early postnatal life, which may serve to protect the testis from precocious Sertoli cell maturation, resulting in proliferation arrest and spermatogenic development.

Anti-mullerian hormone and inhibin B in the definition of ovarian aging and the menopause transition

CONTEXT/OBJECTIVE

The objective of the study was to determine whether anti-Mullerian hormone (AMH) and inhibin B are viable endocrine biomarkers for framing the menopause transition from initiation to the final menstrual period (FMP).

DESIGN

We assayed AMH, inhibin B, and FSH in 300 archival follicular phase specimens from 50 women with six consecutive annual visits commencing in 1993 when all women were in the pre- and perimenopausal menopause stages. Subsequently each woman had a documented FMP. The assay results were fitted as individual-woman profiles and then related to time to FMP and age at FMP as outcomes.

RESULTS

Based on annual values from six time points prior to the FMP, (log)AMH longitudinal profiles declined and were highly associated with a time point 5 yr prior to FMP [including both observed and values below detection (P < 0.0001 and P = 0.0001, respectively)]. Baseline AMH profiles were also associated with age at FMP (P = 0.035). Models of declining (log)inhibin B profiles (including both observed and values below detection) were associated with time to FMP (P < 0.0001 and P = 0.0003, respectively). There was no significant association of (log)inhibin B profiles with age at FMP.

CONCLUSIONS

AMH, an endocrine marker that reflects the transition of resting primordial follicles to growing follicles, declined to a time point 5 yr prior to the FMP; this may represent a critical biological juncture in the menopause transition. Low and nondetectable levels inhibin B levels also were observed 4-5 yr prior to the FMP but were less predictive of time to FMP or age at FMP.

Mullerian inhibiting substance is required for germ cell proliferation during early gonadal differentiation in medaka (Oryzias latipes)

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-beta superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2'-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.

Significance of inhibin B and anti-Müllerian hormone in seminal plasma: a preliminary study

OBJECTIVE

To evaluate the predictive value of seminal inhibin B and anti-Müllerian hormone (AMH) on the outcome of testicular sperm extraction (TESE) in patients with nonobstructive azoospermia.

DESIGN

Prospective study.

SETTING

Reproductive biology department.

PATIENT(S)

Forty-seven normospermic, 28 oligozoospermic, and 68 azoospermic patients.

INTERVENTION(S)

Testicular sperm extraction.

MAIN OUTCOME MEASURE(S)

Seminal inhibin B and AMH measure.

RESULT(S)

The seminal values of inhibin B and AMH are widely dispersed. Both inhibin B and AMH seminal values are significantly different between the three groups. The average rates of seminal AMH (not inhibin B) differ significantly according to the etiology of the azoospermia. Both seminal markers are correlated. A significant positive correlation could be observed between the seminal inhibin B and the sperm count, but not for AMH. A significant correlation also exists between seminal and serum inhibin B. The predictive value for TESE outcome of each parameter is rather low. Conversely, a logistic regression combining serum FSH, seminal inhibin B, and AMH produced a satisfying area under the curve of 0.985.

CONCLUSION(S)

Seminal inhibin B and AMH values are proposed. Separately, seminal markers are poor predictors of TESE outcome. A logistic regression model led to a satisfying area under the curve of 0.985.