Anti-Müllerian hormone attenuates the effects of FSH on follicle development in the mouse ovary

Human ovarian follicular development: from activation of resting follicles to preovulatory maturation

By integrating morphometrical and endocrinological data, as well as biological effects of various molecules synthesized by the human follicle, we propose a dynamic view of the follicle growth within the human ovary. Folliculogenesis starts with entry of resting follicles into the growth phase, a process where the kit system plays a key role. Several months are required for a new growing follicle to reach the preantral stage (0.15mm), then 70 additional days to reach the size of 2mm. Early growing follicle growth is regulated by subtle interactions between follicle-stimulating hormone (FSH) and local factors produced by theca and granulosa cells (GCs), as well as the oocyte. From the time they enter the selectable stage during the late luteal phase, follicles become sensitive to cyclic changes of FSH in terms of granulosa cell proliferation. During the early follicular phase, the early selected follicle grows very quickly and estradiol is present in the follicular fluid. However, the total steroid production remains moderate. From the mid-follicular phase, the preovulatory follicle synthesizes high quantities of estradiol, then after the mid-cycle gonadotropin surge, very large amounts of progesterone. At this stage of development, the responsiveness of the follicle to gonadotropins is maximum, especially to luteinizing hormone (LH) that triggers granulosa wall dissociation and cumulus expansion as well as oocyte nuclear maturation. Thus, as the follicle develops, its responsiveness to gonadotropins progressively increases under the control of local factors acting in an autocrine/paracrine fashion.

[Müllerian inhibitor substance: from gene to protein, its role in clinical practice]

Müllerian inhibiting substance (MIS) has been discovered by Alfred Jost at the beginning of the fifties. MIS is a glycoprotein belonging to the TGF-beta family. Its various functions differ between males and females and according to the age of the individual. In male, the protein is synthesized by Sertoli's cells and induces the disappearance of Müllerian's ducts, the development of the male genital tract. Its role in adult males remains quite unknown. In female, the protein is secreted by granulosa cells and plays a role during folliculogenesis as it regulates the initial and cyclic recruitment of ovarian follicles. MIS is also a good marker of follicular reserve and ovarian function. Therefore, it plays a role in different areas such as assisted medical reproduction and oncology. This protein represents a potential major diagnosis as well as prognostic tool in reproduction.

Association of insulin resistance with anti-Mullerian hormone levels in women without polycystic ovary syndrome (PCOS)

OBJECTIVE

To explore the relationship of insulin resistance (IR) and adipokines (leptin, adiponectin, RBP4) to anti-Mullerian hormone (AMH) levels in women without polycystic ovary syndrome (PCOS).

DESIGN/PATIENTS/MEASUREMENTS

We recruited 120 healthy, reproductive age women without PCOS. An overnight fasting blood draw, anthropometric measurements, analyses of serum levels of AMH, adipokines (leptin, adiponectin and RBP4) and total testosterone, a homeostasis model assessment for insulin resistance (HOMA-IR) and a transvaginal ultrasound scan were performed between the third and fifth day of their spontaneous menstrual cycles.

RESULTS

Higher HOMA-IR levels were associated with lower levels of AMH. After adjustment for age, serum AMH levels negatively correlated with insulin, fasting glucose, HOMA-IR and RBP4. However, a positive correlation was identified between serum AMH and adiponectin. A final multiple stepwise linear regression demonstrated that HOMA-IR was independently associated with AMH.

CONCLUSION

An independent relationship exists between HOMA-IR and AMH in women without PCOS, possibly due to the effect of abnormal insulin action on AMH secretion by granulosa cells.

Gonadotropin releasing hormone antagonists suppress aromatase and anti-Müllerian hormone expression in human granulosa cells

OBJECTIVE

To investigate the effects of a gonadotropin-releasing hormone antagonist (GnRH-ANT) on the expression of anti-Müllerian Hormone (AMH) and aromatase (via the exon CYP19IIa promoter), in cultured human granulosa cells (hGCs) and the human granulosa cell line (HGL5).

DESIGN

Primary cell cultures of hGCs and culture of HGL5 cells.

SETTING

Academic center.

PATIENT(S)

Women undergoing IVF because of male factor, tubal infertility, or donor eggs.

INTERVENTION(S)

hGCs and HGL5 cells were treated with a GnRH-ANT (1 nM and 1 μM) alone or in combination with cAMP (1 mM). Media was collected and stored at -80°C until assayed.

MAIN OUTCOME MEASURE(S)

mRNA levels of CYP19 IIa, AMH, steroidogenic factor 1 (SF-1) and liver receptor homologue-1 (LRH-1) were determined by quantitative polymerase chain reaction. ELISA was used to determined estradiol (E(2)) levels in the culture media. Pooled results from triplicate experiments were analyzed using one-way analysis of variance with Student-Newman-Keuls multiple-comparison methods.

RESULT(S)

The GnRH-ANT decreased the expressions of CYP19 IIa, AMH, SF-1, and LRH-1. cAMP induced aromatase and AMH expression. Cotreatment with cAMP and GnRH-ANT caused a dose-dependent suppression of AMH and CYP19 IIa mRNA. A GnRH agonist (GnRH-A) increased the mRNA expressions of CYP 19 IIa and AMH. The GnRH-ANT decreased E(2) production in cultured hGCs.

CONCLUSION(S)

GnRH-ANTs, in addition to their central suppressive effects on the pituitary, may have a direct effect on ovarian granulosa cells with inhibition of aromatase and AMH expression. Furthermore, the inhibitory effect could be mediated via suppression of SF-1 and LRH-1, and may play a role in estrogen-mediated ovarian folliculogenesis.

Testosterone-induced downregulation of anti-Müllerian hormone expression in granulosa cells from small bovine follicles

Polycystic ovary syndrome (PCOS) is characterized by the presence of hyperandrogenism and an increased follicular mass probably determined by deregulation of locally produced factors. Anti-Müllerian hormone (AMH) is a glycoprotein that inhibits follicular recruitment and determines the size of the follicular pool. To evaluate the role of androgens in the regulation of AMH expression in bovine granulosa cells from small follicles, granulosa cells from 3 to 4 mm follicles were isolated and incubated in basal culture media, or in media containing testosterone (T) at 10(-5)M, T 10(-8)M, or estradiol (E2) at 150 ng/ml for 48 h. AMH mRNA levels of these cells were determined using real-time PCR (RT PCR). AMH protein levels and E2 were determined in cell-conditioned media. A 3.4-fold decrease in AMH mRNA levels was observed in granulosa cells exposed to T 10(-5)M (P = 0.03, n = 5), but not in cells exposed to T 10(-8)M. AMH protein levels showed a 1.8-fold reduction in cell-conditioned media from cells exposed to T 10(-5)M (P = 0.01, n = 5), without significant changes in the group exposed to T 10(-8)M. Cells treated with E2 150 ng/ml showed no change in AMH protein levels. We propose that AMH expression is modulated by androgens in bovine granulosa cells from small follicles. Thus, it is possible to speculate that androgens, by inhibiting AMH expression, may promote follicle recruitment, increasing the early growing follicular pool. This new mechanism may have implications for the understanding of PCOS pathophysiology.

Impact of female age and male infertility on ovarian reserve markers to predict outcome of assisted reproduction technology cycles

BACKGROUND

This study was designed to assess the capability of ovarian reserve markers, including baseline FSH levels, baseline anti-Müllerian hormone (AMH) levels, and antral follicle count (AFC), as predictors of live births during IVF cycles, especially for infertile couples with advanced maternal age and/or male factors.

METHODS

A prospective cohort of 336 first IVF/ICSI cycles undergoing a long protocol with GnRH agonist was investigated. Patients with endocrine disorders or unilateral ovaries were excluded.

RESULTS

Among the ovarian reserve tests, AMH and age had a greater area under the receiving operating characteristic curve than FSH in predicting live births. Furthermore, AMH and age were the sole predictive factors of live births for women greater than or equal to 35 years of age; while AMH was the major determinant of live births for infertile couples with absence of male factors by multivariate logistic regression analysis. However, all the studied ovarain reserve tests were not preditive of live births for women < 35 years of age or infertile couples with male factors.

CONCLUSION

The serum AMH levels were prognostic for pregnancy outcome for infertile couples with advanced female age or absence of male factors. The predictive capability of ovarian reserve tests is clearly influenced by the etiology of infertility.

Ovarian aging in squirrel monkeys (Saimiri sciureus)

In female squirrel monkeys (Saimiri sciureus), the reproductive period normally extends from approximately 2.5 years to the mid-teens. In the present study, we examined the age-associated cytological changes in the ovaries of 24 squirrel monkeys ranging in age from newborn to approximately 20 years. We found a significant, age-related decline in the number of primordial follicles, with the most pronounced loss occurring between birth and 5 years. After approximately 8 years of age, relatively few primordial follicles were evident in the ovarian sections examined. An unusual feature of the aging squirrel monkey ovary is the emergence of highly differentiated, encapsulated clusters of granulosa cells that increase in size and number, particularly after the age of 8 years. Many of these cells express anti-Müllerian hormone, and, histologically, the clusters resemble granulosa cell tumors in humans. However, granulosa cell clusters (GCCs) are present in both ovaries of all older squirrel monkeys, and they display no obvious signs of malignancy, suggesting that they are a normal feature of ovarian aging in this species. Our findings indicate that reproductive senescence in female squirrel monkeys, as in other primates, involves the inexorable depletion of ovarian follicles. In addition, the consistent appearance of abundant, well-differentiated clusters of granulosa cells in older squirrel monkeys, prior to the cessation of reproduction, suggests that these structures may influence the later stages of reproductive potential in this species. Analysis of GCCs in older squirrel monkeys also could yield insights into the pathophysiology of granulosa cell tumors in humans.

Ovarian aging: mechanisms and clinical consequences

Menopause is the final step in the process referred to as ovarian ageing. The age related decrease in follicle numbers dictates the onset of cycle irregularity and the final cessation of menses. The parallel decay in oocyte quality contributes to the gradual decline in fertility and the final occurrence of natural sterility. Endocrine changes mainly relate to the decline in the negative feedback from ovarian factors at the hypothalamo-pituitary unit. The declining cohort of antral follicles with age first results in gradually elevated FSH levels, followed by subsequent stages of overt cycle irregularity. The gradual decline in the size of the antral follicle cohort is best represented by decreasing levels of anti-Mullerian hormone. The variability of ovarian ageing among women is evident from the large variation in age at menopause. The identification of women who have severely decreased ovarian reserve for their age is clinically relevant. Ovarian reserve tests have appeared to be fairly accurate in predicting response to ovarian stimulation in the assisted reproductive technology (ART) setting. The capacity to predict the chances for spontaneous pregnancy or pregnancy after ART appears very limited. As menopause and the preceding decline in oocyte quality seem to have a fixed time interval, tests that predict the age at menopause may be useful to assess individual reproductive lifespan. Especially genetic studies, both addressing candidate gene and genome wide association, have identified several interesting loci of small genetic variation that may determine fetal follicle pool development and subsequent wastage of his pool over time. Improved knowledge of the ovarian ageing mechanisms may ultimately provide tools for prediction of menopause and manipulation of the early steps of folliculogenesis for the purpose of contraception and fertility lifespan extension.

FSHbeta knockout mouse model: a decade ago and into the future

In 1997, more than 10 years ago now, we first reported the phenotypes of follicle stimulating hormone (FSH) beta null mice. Since then, these mice have been useful for various physiological and genetic studies in reproductive biology. More recently, extra-gonadal functions of FSH have been discovered in bone. These studies opened up exciting avenues of new research on osteoporosis in postmenopausal women. Several genomics and proteomics tools and novel strategies to spatio-temporally restricting gene expression in vivo are available now. It is hoped that with the aid of these and other emerging technologies, an integrated network of FSH signaling pathways in various tissues would emerge in the near future. Undoubtedly, the coming 10 years should be more exciting to explore this "fertile" area of reproductive physiology research.

Molecular mechanisms underlying the activation of mammalian primordial follicles

In humans and other mammalian species, the pool of resting primordial follicles serves as the source of developing follicles and fertilizable ova for the entire length of female reproductive life. One question that has intrigued biologists is: what are the mechanisms controlling the activation of dormant primordial follicles. Studies from previous decades have laid a solid, but yet incomplete, foundation. In recent years, molecular mechanisms underlying follicular activation have become more evident, mainly through the use of genetically modified mouse models. As hypothesized in the 1990s, the pool of primordial follicles is now known to be maintained in a dormant state by various forms of inhibitory machinery, which are provided by several inhibitory signals and molecules. Several recently reported mutant mouse models have shown that a synergistic and coordinated suppression of follicular activation provided by multiple inhibitory molecules is necessary to preserve the dormant follicular pool. Loss of function of any of the inhibitory molecules for follicular activation, including PTEN (phosphatase and tensin homolog deleted on chromosome 10), Foxo3a, p27, and Foxl2, leads to premature and irreversible activation of the primordial follicle pool. Such global activation of the primordial follicle pool leads to the exhaustion of the resting follicle reserve, resulting in premature ovarian failure in mice. In this review, we summarize both historical and recent results on mammalian primordial follicular activation and focus on the up-to-date knowledge of molecular networks controlling this important physiological event. We believe that information obtained from mutant mouse models may also reflect the molecular machinery responsible for follicular activation in humans. These advances may provide a better understanding of human ovarian physiology and pathophysiology for future clinical applications.

Association study of AMH and AMHRII polymorphisms with unexplained infertility

OBJECTIVE

To investigate the association of AMH and AMHRII polymorphisms with reproductive abilities in a sample of women with idiopathic infertility.

DESIGN

Case-control study.

SETTING

University Department of Obstetrics and Gynecology, and University Unit of Clinical Genetics.

PATIENT(S)

76 women with idiopathic sterility and 100 fertile women as controls.

INTERVENTION(S)

Genotyping was performed by high-resolution melt analysis.

MAIN OUTCOME MEASURE(S)

Genotype distribution and allele frequency of AMH and AMHRII polymorphisms. Reconstruction of haplotype alleles to evaluate the linkage disequilibrium between single nucleotide polymorphisms.

RESULT(S)

Allele frequencies of -482 A>G, IVS 5-6 C>T, IVS 10+77 A>G, 146T>G polymorphisms are statistically significantly different in infertile patients compared with controls.

CONCLUSION(S)

Genetic variants of AMH and AMHRII genes seem to be associated with infertility, suggesting a role in the pathophysiology of normo-estrogenic and normo-ovulatory infertility. A clearer understanding of their function in ovarian physiology may help clinicians to find a role for antimüllerian hormone measurement in the field of reproductive medicine.

Prediction of high ovarian response to controlled ovarian hyperstimulation: anti-Müllerian hormone versus small antral follicle count (2-6 mm)

PURPOSE

To evaluate the predictive value of basal serum anti-müllerian hormone level and small antral follicle count for high ovarian response to controlled ovarian hyperstimulation.

METHODS

A total of 159 patients were prospectively included. Basal serum anti-müllerian hormone and small antral follicle count (2-6 mm) were measured.

RESULTS

Small antral follicle count and anti-müllerian hormone have similar predictive accuracy for high ovarian response with area under curve of 0.961 and 0.922, respectively. The sensitivity and specificity for prediction of high ovarian response were 89% and 92% for small antral follicle count and 93% and 78% for anti-müllerian hormone at the cutoff values of > or = 16 and > or = 34.5 pmol/l, respectively.

CONCLUSIONS

Small antral follicle count and anti-müllerian hormone are equally accurate predictors of high ovarian response and facilitate determination of the optimal strategy for controlled ovarian hyperstimulation.

Follicular fluid levels of anti-Mullerian hormone as a predictor of oocyte maturation, fertilization rate, and embryonic development in patients with polycystic ovary syndrome

OBJECTIVE

To test whether the follicular fluid (FF) concentration of anti-Mullerian hormone (AMH) is associated with oocyte maturation, fertilization rate, and embryonic development in patients with polycystic ovary syndrome (PCOS) undergoing IVF.

DESIGN

Prospective.

SETTING

Academic assisted reproductive technology program.

PATIENT(S)

Twenty-two samples of FF from 11 patients with PCOS who underwent IVF/ET were analyzed for AMH levels (group A). Twelve women with normal ovulatory cycles served as a control group (group B). The oocytes and preembryos were closely followed until ET.

METHOD(S)

FF was obtained at oocyte retrieval for IVF/intracytoplasmic sperm injection. AMH levels were studied using immunoenzymometric assay.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

FF, AMH levels, oocyte maturation, fertility rate, and embryonic cleavage rate.

RESULT(S)

The mean FF AMH level was 57.3 +/- 79.5 pmol/mL in group A, compared with 70 +/- 120.14 pmol/mL in group B. In group A, the mean AMH level of good-quality embryos was 37.4 +/- 23.4 pmol/mL, compared with 61.9 +/- 102 pmol/mL in a the poor-quality subgroup. No significant correlation was observed between FF AMH levels and oocyte maturation, fertilization, or cleavage rate.

CONCLUSION(S)

This study suggests that there is an association between FF AMH levels and the quality of embryos in patients with PCOS. However, owing to large variance and the number of participants, no statistical significance was reached. The degree of maturation of retrieved oocytes, as well as the success of fertilization, was not found to correlate with FF AMH.

Anti-Mullerian hormone levels reflect severity of PCOS but are negatively influenced by obesity: relationship with increased luteinizing hormone levels

The objective of the study was the comparison of anti-Müllerian hormone (AMH) levels among obese or overweight and normal-weight women with the four different polycystic ovary syndrome (PCOS) phenotypes and healthy control subjects. AMH levels were evaluated in four age- and body mass index (BMI)-matched groups of 25 normal-weight and 25 obese or overweight women each, belonging to the four main subsets of the syndrome resulting from combinations of the three diagnostic criteria [group 1: oligo- and/or anovulation (ANOV), hyperandrogenemia (HA), and polycystic ovaries (PCO) on ultrasonographic evaluation; group 2: ANOV and HA; group 3: HA and PCO, group 4: ANOV and PCO], and in 50 (25 obese or overweight and 25 normal weight) age- and BMI-matched healthy control subjects. Age, BMI, waist circumference, FSH, LH, prolactin, testosterone, Delta(4)-androstenedione, dehydroepiandrosterone-sulfate, 17alpha-OH-progesterone, fasting insulin, glucose, AMH, free androgen index, and homeostasis model assessment for insulin resistance index were analyzed. AMH levels were significantly higher in PCOS groups 1 and 2 compared with groups 3 and 4 and the control group and higher in PCOS groups 3 and 4 compared with the control group. AMH levels were significantly increased in normal-weight compared with obese and overweight women. AMH concentrations were independently predicted, in order of significance, by LH and testosterone levels, BMI (negatively), and the total number of follicles 2-9 mm in diameter. The differences in circulating AMH levels between the main phenotypic groups of PCOS women appear to reflect the severity of the syndrome, but are negatively affected by obesity. Increased LH levels might be the most significant independent link between PCOS-associated disorders of ovulation and the observed increase in circulating AMH concentration.

Variation in the ovarian reserve is linked to alterations in intrafollicular estradiol production and ovarian biomarkers of follicular differentiation and oocyte quality in cattle

The mechanisms whereby the high variation in numbers of morphologically healthy oocytes and follicles in ovaries (ovarian reserve) may have an impact onovarian function, oocyte quality, and fertility are poorly understood. The objective was to determine whether previously validated biomarkers for follicular differentiation and function, as well as oocyte quality differed between cattle with low versus a high antral follicle count (AFC). Ovaries were removed (n = 5 per group) near the beginning of the nonovulatory follicular wave, before follicles could be identified via ultrasonography as being dominant, from heifers with high versus a low AFC. The F1, F2, and F3 follicles were dissected and diameters determined. Follicular fluid and thecal, granulosal, and cumulus cells and the oocyte were isolated and subjected to biomarker analyses. Although the size and numerous biomarkers of differentiation, such as mRNAs for the gonadotropin receptors, were similar, intrafollicular concentrations of estradiol and the abundance of mRNAs for CYP19A1 in granulosal cells and ESR1, ESR2, and CTSB in cumulus cells were greater, whereas mRNAs for AMH in granulosal cells and TBC1D1 in thecal cells were lower for animals with low versus a high AFC during follicle waves. Hence, variation in the ovarian reserve may have an impact on follicular function and oocyte quality via alterations in intrafollicular estradiol production and expression of key genes involved in follicle-stimulating hormone action (AMH) and estradiol (CYP19A1) production by granulosal cells, function and survival of thecal cells (TBC1D1), responsiveness of cumulus cells to estradiol (ESR1, ESR2), and cumulus cell determinants of oocyte quality (CTSB).

B-vitamin and homocysteine status determines ovarian response to gonadotropin treatment in sheep

Maternal B-vitamin status and homocysteinemia can affect fertility and pregnancy establishment, although the direct effects on ovarian follicle and oocyte development are not known. We report on the effects of restricting the supply of vitamin B(12) and methionine from the diet of mature female sheep on ovarian folliculogenesis following follicle-stimulating hormone (FSH) stimulation. The study was split into three batches and involved 76 animals. Surprisingly, the number of growing, estrogen-active antral follicles following FSH treatment was enhanced (P = 0.005) following this dietary intervention. This increase occurred even in the presence of modest live-weight loss (batch 1 only) and depressed plasma insulin concentrations, suggesting a breakdown in the regulation of follicular responsiveness to FSH. This dietary intervention also increased plasma homocysteine concentrations. Physiological concentrations of homocysteine increased granulosa cell proliferation (P < 0.001), estradiol production (P = 0.05), and FSHR transcript expression (P = 0.017) during culture. Transcript levels for growth differentiation factor 9 and bone morphogenetic protein 15 in oocytes from treated ewes were increased (P < 0.05) in the first two batches. Furthermore, regression of BMP receptor 2 (BMPR2) transcript expression and diet on follicle number revealed a significant interaction (P = 0.01); BMPR2 transcript expression was associated with follicle number only in vitamin B(12)/methionine-restricted animals. Because FSHR transcript expression also was positively (P = 0.007) related to follicle number, the effects of diet may have arisen through enhanced FSH and BMP signaling. Although this remains to be confirmed, the data support an intraovarian impact of vitamin B(12)/methionine-deficient diets.

The role of mullerian inhibiting substance in female reproduction

PURPOSE OF REVIEW

To review the role of mullerian inhibiting substance in the context of female reproduction.

RECENT FINDINGS

Serum and follicular fluid mullerian inhibiting substance can be measured by commercially available enzyme-linked immunosorbent assay kits. Mullerian inhibiting substance is secreted from small antral follicles with minimal fluctuation throughout the menstrual cycle. The exact biological functions of mullerian inhibiting substance are uncertain; however, mullerian inhibiting substance most likely mediates follicle recruitment and selection, and may inhibit aromatase activity. Most data suggests an interaction between follicle-stimulating hormone, and mullerian inhibiting substance although the exact nature of the relationship is unknown. Mullerian inhibiting substance is characteristically elevated in polycystic ovarian syndrome, and may be associated with other features of polycystic ovary syndrome such as insulin resistance, hyperandrogenemia, and the degree of anovulation. Mullerian inhibiting substance changes have also been associated with functional hypothalamic amenorrhea, premature ovarian failure, endometriosis and obesity. Mullerian inhibiting substance has been studied extensively in the context of in-vitro fertilization and has been correlated with several outcome parameters.

SUMMARY

Mullerian inhibiting substance is gaining acceptance as a useful marker of female reproductive function, especially with ovulatory disorders and IVF outcomes. Mullerian inhibiting substance offers several advantages to existing screening tests, but establishment of an assay standard should be considered before widespread clinical implementation becomes viable.

Variants in the ACVR1 gene are associated with AMH levels in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovaries display an increased number of pre-antral and antral follicles compared with normal ovaries, suggesting that early and late follicle development are disturbed. The pathophysiology of this process is poorly understood. Since the transforming growth factor beta family members, anti-Müllerian hormone (AMH) and bone morphogenetic proteins (BMPs), inhibit FSH sensitivity, their signalling may contribute to the aberrant follicle development in these women. Here, we investigated the role of ALK2, a type I receptor for AMH/BMP signalling, in PCOS using a genetic approach.

METHODS

Seven single nucleotide polymorphisms in the ACVR1 gene, encoding ALK2, were genotyped in 359 PCOS patients and 30 normo-ovulatory and 3543 population-based control women, and haplotypes were determined. Subsequently, the association of ACVR1 variants with ovarian parameters and hormone levels was investigated.

RESULTS

The polymorphisms rs1220134, rs10497189 and rs2033962 and their corresponding haplotypes did not show different frequencies from controls, but were associated with AMH levels in PCOS women (P = 0.001, P = 0.002 and P = 0.007, respectively). Adjustment for follicle number revealed that the association with AMH levels was, in part, independent from follicle number, suggesting that variants in ACVR1 also influence AMH production per follicle.

CONCLUSIONS

Genetic variation within ACVR1 is associated with AMH levels and follicle number in PCOS women, suggesting that ALK2 signalling contributes to the disturbed folliculogenesis in PCOS patients.

Follicle stimulating hormone and its rate of change in defining menopause transition stages

CONTEXT/OBJECTIVE

The objective of the study was to identify menopause transition stages using acceleration or deceleration patterns of FSH rates of change from the late reproductive years to postmenopause.

SETTING/PARTICIPANTS

Participants were the Michigan Bone Health and Metabolism Study cohort of 629 women, aged 24-44 yr (in 1992/3), with 5757 annual FSH data points over a 14-yr period. DESIGN/MAIN OUTCOME MEASURES: The study was designed to relate acceleration/deceleration patterns in FSH rate of change to time to final menstrual period (FMP) and chronological age using nonparametric and piecewise regression modeling.

RESULTS

Four major FSH stages, based on rate of FSH change patterns, were identifiable in relation to the FMP. In FSH stage 1, the rate of FSH change increased modestly up to -7 yr prior to the FMP; in FSH stage 2 (-7 to -2 yr prior to FMP), there was a major acceleration in FSH rate of change. FSH stage 3 had an acute increase in FSH rate of change (-2 to +1 yr around the FMP), with average FSH level of 34 mIU/ml. The fourth, or plateau, FSH stage began at 1 yr after FMP when the average FSH level was 54 mIU/ml. During the yr 28-60, there were eight age-specific epochs defined by significant changes of FSH trajectory accelerations or decelerations and rate of change.

CONCLUSIONS

Four menopause transition stages bounding the FMP and eight epochs in chronological aging from age 28 to 60 yr were defined by changes of FSH trajectory accelerations/decelerations and rates of change. This timing information, combined with knowledge of FSH levels and menstrual cycle characteristics, can help discern the likely status of women with respect to their reproductive viability and menopause transition stage.

Developmental methoxychlor exposure affects multiple reproductive parameters and ovarian folliculogenesis and gene expression in adult rats

Methoxychlor (MXC) is an organochlorine pesticide with estrogenic, anti-estrogenic, and anti-androgenic properties. To investigate whether transient developmental exposure to MXC could cause adult ovarian dysfunction, we exposed Fischer rats to 20 microg/kg/day (low dose; environmentally relevant dose) or 100 mg/kg/day (high dose) MXC between 19 days post coitum and postnatal day 7. Multiple reproductive parameters, serum hormone levels, and ovarian morphology and molecular markers were examined from prepubertal through adult stages. High dose MXC accelerated pubertal onset and first estrus, reduced litter size, and increased irregular cyclicity (P<0.05). MXC reduced superovulatory response to exogenous gonadotropins in prepubertal females (P<0.05). Rats exposed to high dose MXC had increasing irregular estrous cyclicity beginning at 4 months of age, with all animals showing abnormal cycles by 6 months. High dose MXC reduced serum progesterone, but increased luteinizing hormone (LH). Follicular composition analysis revealed an increase in the percentage of preantral and early antral follicles and a reduction in the percentage of corpora lutea in high dose MXC-treated ovaries (P<0.05). Immunohistochemical staining and quantification of the staining intensity showed that estrogen receptor beta was reduced by high dose MXC while anti-Mullerian hormone was upregulated by both low- and high dose MXC in preantral and early antral follicles (P<0.05). High dose MXC significantly reduced LH receptor expression in large antral follicles (P<0.01), and down-regulated cytochrome P450 side-chain cleavage. These results demonstrated that developmental MXC exposure results in reduced ovulation and fertility and premature aging, possibly by altering ovarian gene expression and folliculogenesis.

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.

Ovarian reserve evaluation: state of the art

PURPOSE

Revise role of hormonal basal and dynamic tests, as well as ultrasonographic measures as ovarian reserve markers, in order to provide better counseling to subfertile couples.

METHODS

Review of publications on the topic, with an emphasis on recent well designed articles.

RESULTS

Currently available ovarian reserve tests do not provide sufficient evidence to be solely considered ideal, even for premature ovarian senescence patients who do not present subfertility complaints. However, these markers occupy important place in initial approach to treatment of subfertile couples, predicting unsatisfactory results that could be improved by differentiated induction schemes and reducing excessive psychological and financial burdens, and adverse effects.

CONCLUSIONS

In order to remedy the limitations due to the scarcity of strong evidence about this topic, future studies should try to clarify predictive value of markers in groups of specific diseases-related subfertility and pay special attention to propaedeutic multivariate models including anti-Müllerian hormone and antral follicle count.

Effect of pituitary desensitization on the early growing follicular cohort estimated using anti-Mullerian hormone

BACKGROUND

This study evaluated the effect of pituitary desensitization on the early growing follicle population through assessment of serum anti-Mullerian hormone (AMH) concentration. Other markers of ovarian reserve, basal follicular stimulating hormone (FSH), luteinizing hormone (LH), estradiol, inhibin-B and three-dimensional ultrasound ovarian parameters were also assessed for comparison.

METHODS

One hundred and two subjects aged <40 years with FSH levels <12 IU/l underwent venepuncture and transvaginal ultrasound in the early follicular phase of the menstrual cycle and after 14 days of down-regulation using gonadotrophin releasing hormone (GnRH) agonists. Serum levels of AMH and other markers of ovarian reserve measured during the early follicular phase were compared with those measured following down-regulation.

RESULTS

While AMH levels increased significantly by approximately 32% (P < 0.01), there was a significant decline of approximately 40-50% (P < 0.01) in the levels of inhibin-B, FSH, LH and estradiol. Down-regulation treatment was also associated with a decrease (P < 0.01) in mean ovarian volume and in ovarian blood flow, but no difference was seen in the antral follicle count.

CONCLUSIONS

Pituitary desensitization results in a significant increase in AMH levels, which implies that either the secretion of AMH by early growing follicles is enhanced or that the size of this follicle cohort is increased. The number of antral follicles visualized on ultrasound in the early follicular phase and at down-regulation appears unchanged, suggesting that any effect is restricted to the smaller selectable follicles. Our results may explain the enhanced ovarian response to conventional controlled ovarian stimulation and higher pregnancy rates when pretreatment with GnRH-agonists is employed.

Oogenesis: Prospects and challenges for the future

Oogenesis serves a singular role in the reproductive success of plants and animals. Of their remarkable differentiation pathway what stands out is the ability of oocytes to transform from a single cell into the totipotent lineages that seed the early embryo. As our understanding that commonalities between diverse organisms at the genetic, cellular and molecular levels are conserved to achieve successful reproduction, the notion that embryogenesis presupposes oogenesis has entered the day-to-day parlance of regenerative medicine and stem cell biology. With emphasis on the mammalian oocyte, this review will cover (1) current concepts regarding the birth, survival and growth of oocytes that depends on complex patterns of cell communication between germ line and soma, (2) the notion of "maternal inheritance" from a genetic and epigenetic perspective, and (3) the relative value of model systems with reference to current clinical and biotechnology applications.

The ovary: anatomy and function throughout human life

A prerequisite to the understanding of the ovarian diseases and infertility is a thorough understanding of normal embryology and physiology of the ovary. Therefore, the objective of this review article is to provide brief and updated information on the molecular basis of the events that control gonadal development, germ cell formation, folliculogenesis, and ovulation.

A mesenchymal perspective of Müllerian duct differentiation and regression in Amhr2-lacZ mice

The Müllerian ducts give rise to the female reproductive tract, including the Fallopian tubes, uterus, cervix, and anterior vagina. In male embryos, the Müllerian ducts regress, preventing the formation of female organs. We introduced the bacterial lacZ gene, encoding beta-galactosidase (beta-gal), into the AMHR-II locus (Amhr2) by gene targeting in mouse embryonic stem (ES) cells to mark Müllerian duct differentiation and regression. We show that Amhr2-lacZ heterozygotes express beta-gal activity in an Amhr2-specific pattern. In the gonads, beta-gal activity was detected in Sertoli cells of the testes from 2 weeks after birth, and fetal ovaries and granulosa cells of the adult ovary. beta-gal activity was first detected in the rostral mesenchyme of the Müllerian ducts at 12.5 days post coitus (dpc) in both sexes but soon thereafter expression was found along the entire length of the Müllerian ducts with higher levels initially found in males. In females, beta-gal activity was restricted to one side of the ductal mesoepithelium, whereas in males beta-gal expression encircled the duct. beta-gal activity was also detected in the coelomic epithelium at 13.5 and 14.5 dpc. In male embryos, mesenchymal beta-gal activity permitted the visualization of the temporal and spatial pattern of Müllerian duct regression. This pattern was similar to that observed using a Müllerian duct mesoepithelium lacZ reporter, indicating a coordinated loss of Müllerian duct mesoepithelium and Amhr2-expressing mesenchyme.

Concentration of anti-Müllerian hormone and inhibin-B in relation to steroids and age in follicular fluid from small antral human follicles

CONTEXT

Ovaries surgically removed for fertility preservation served as a source of follicle fluid from human small antral follicles.

OBJECTIVE

The objective of the study was to measure intrafollicular concentrations of anti-Müllerian Hormone (AMH), inhibin-B, progesterone, androstenedione, testosterone, estradiol, and IGF binding protein-4.

SETTING

The study was conducted at a university hospital.

PATIENTS

Patients included 43 women having one ovary removed prior to receiving gonadotoxic treatment due to malignant disease.

INTERVENTIONS

Fluid from 100 follicles (diameter of 3-9 mm) were included.

MAIN OUTCOME MEASURES

Intrafollicular concentrations of the measured hormones, their possible intercorrelation, and correlation with age were measured.

RESULTS

Concentrations of AMH were unrelated to follicular fluid concentrations of androstenedione and testosterone. There was a significant negative correlation between estradiol, inhibin-B, progesterone, and AMH. In four age groups spanning 11-37 yr, levels of AMH, estradiol, androstenedione, testosterone and inhibin-B remained constant, whereas progesterone showed significant variations. IGF binding protein-4 was unrelated to any other measured hormone.

CONCLUSIONS

This study was unable to confirm a stimulatory effect of androgens on AMH secretion but did enforce a close intimate correlation between AMH and estradiol expressions in the developing human follicle. The insignificant variation of the AMH concentration with age, even in prepubertal girls, suggests that AMH expression is unrelated to menstrual cycle FSH cyclicity.

Gene expression profiling during early folliculogenesis in the mouse ovary

OBJECTIVE

To evaluate genes involved in ovarian primordial-to-primary follicle transition.

DESIGN

Experimental animal study.

SETTING

Research institute.

ANIMAL(S)

Day-2 and day-4 female Swiss mice.

INTERVENTION(S)

We conducted a complementary DNA array study using ovarian messenger RNAs from day-2 and day-4 mice.

MAIN OUTCOME MEASURE(S)

The expression profiles of 1,176 genes in neonatal mouse ovaries on day 2 and day 4, which contain primordial and primary follicles, respectively, were compared.

RESULT(S)

Twenty-six percent of genes were differentially expressed between day-2 and day-4 ovaries, with 19% being up-regulated and 7% down-regulated in day 4. Analysis of differentially expressed genes revealed that the primordial-to-primary follicle stage transition is associated with induction in the expression of mainly growth factors, immune-related factors, hormone and hormone receptors, and signal transducers. The transition is also associated with proliferation of granulosa cells and absence of apoptosis. In addition, our studies demonstrated that the primary follicles express estrogen receptor beta and are responsive to estrogen actions in vitro in terms of increase in the number of primary follicles and granulosa cell proliferation.

CONCLUSION(S)

The transition of primordial to primary follicles is associated with the participation of multiple pathways in regulating gene expression.

Photoperiod-dependent modulation of anti-Müllerian hormone in female Siberian hamsters, Phodopus sungorus

Fertility and fecundity decline with advancing age in female mammals, but reproductive aging was decelerated in Siberian hamsters (Phodopus sungorus) raised in a short-day (SD) photoperiod. Litter success was significantly improved in older hamsters when reared in SD and the number of primordial follicles was twice that of females held in long days (LD). Because anti-Müllerian hormone (AMH) appears to inhibit the recruitment of primordial follicles in mice, we sought to determine whether the expression patterns of AMH differ in the ovaries and serum of hamsters raised in SD versus LD. Ovaries of SD female hamsters are characterized by a paucity of follicular development beyond the secondary stage and are endowed with an abundance of large eosinophilic cells, which may derive from granulosa cells of oocyte-depleted follicles. In ovaries from 10-week-old SD hamsters, we found that the so-called 'hypertrophied granulosa cells' were immunoreactive for AMH, as were granulosa cells within healthy-appearing primary and secondary follicles. Conversely, ovaries from age-matched LD animals lack the highly eosinophilic cells present in SD ovaries. Therefore, AMH staining in LD was limited to primary and secondary follicles that are comparable in number to those found in SD ovaries. The substantially greater AMH expression in SD ovaries probably reflects the abundance of hypertrophied granulosa cells in SD ovaries and their relative absence in LD ovaries. The modulation of ovarian AMH by day length is a strong mechanistic candidate for the preservation of primordial follicles in female hamsters raised in a SD photoperiod.

Müllerian-inhibiting substance inhibits cytochrome P450 aromatase activity in human granulosa lutein cell culture

OBJECTIVE

To investigate the effects of Müllerian-inhibiting substance (MIS) on cytochrome P450 aromatase (CYP19) gene expression in cultured human granulosa lutein cells (GLC).

DESIGN

In vitro primary cell culture study.

SETTING

Academic research laboratory and hospital-based fertility center.

PATIENT(S)

Eight normo-ovulatory patients undergoing IVF procedures due to male factor or tubal infertility.

INTERVENTION(S)

Serum and follicular fluid (FF) collected and stored at -80 degrees C until assayed. Granulosa lutein cells were harvested from follicular aspirates obtained during oocyte retrieval and cultured for 7 days with media in the presence or absence of MIS (10 ng/mL) or FSH 0.2 IU/mL.

MAIN OUTCOME MEASURE(S)

Serum and FF levels of E2 and MIS, and E2 production by GLC in culture. Levels of CYP19 mRNA in cultured GLC were determined by quantitative polymerase chain reaction (PCR) and CYP19 protein by Western blot. Statistical comparison used ANOVA and post hoc Tukey tests.

RESULT(S)

Follicle-stimulating hormone significantly increased E2 production in cultured GLC compared with control. The increase in E2 production is associated with higher levels of CYP19 mRNA and protein in GLC. The presence of MIS significantly inhibited FSH-induced E2 production, with concomitant reduction in CYP19mRNA and protein levels.

CONCLUSION(S)

Müllerian-inhibiting substance inhibits FSH augmentation of CYP19 enzyme activity and CYP19 gene expression in GLC. These findings may help to explain the association of high MIS levels and low FF E2 levels reported in women with polycystic ovary syndrome (PCOS).

Intrafollicular steroids and anti-mullerian hormone during normal and cystic ovarian follicular development in the cow

Development of follicular cysts is a frequent ovarian dysfunction in cattle. Functional changes that precede cyst formation are unknown, but a role for anti-Müllerian hormone (AMH) in the development of follicular cysts has been suggested in humans. This study aimed to characterize intrafollicular steroids and AMH during follicular growth in a strain of beef cows exhibiting a high incidence of occurrence of follicular cysts. Normal follicular growth and cyst development were assessed by ovarian ultrasonography scanning during the 8 days before slaughtering. Experimental regression of cysts was followed by rapid growth of follicles that reached the size of cysts within 3-5 days. These young cysts exhibited higher intrafollicular concentrations of testosterone, estradiol-17beta, and progesterone than large early dominant follicles did in normal ovaries, but they exhibited similar concentrations of AMH. Later-stage cysts were characterized by hypertrophy of theca interna cells, high intrafollicular progesterone concentration, and high steroidogenic acute regulatory protein mRNA expression in granulosa cells. Progesterone and AMH concentrations in the largest follicles (> or =10 mm) and cysts were negatively correlated (r = -0.45, P < 0.01). Smaller follicles (<10 mm) exhibited higher intrafollicular testosterone and estradiol-17beta concentrations in ovaries with cysts compared to normal ovaries. During follicular growth, AMH concentration dropped in follicles larger than 5 mm in diameter and in a similar way in ovaries with and without cysts. In conclusion, enhanced growth and steroidogenesis in antral follicles <10 mm preceded cyst formation in cow ovaries. Intrafollicular AMH was not a marker of cystic development in the cow, but low AMH concentrations in cysts were associated with luteinization.

Regulation of Pcsk6 Expression During the Preantral to Antral Follicle Transition in Mice: Opposing Roles of FSH and Oocytes1

Several secreted products of the TGFbeta superfamily have important roles during follicular development and are produced by both oocytes and somatic cells (granulosa and theca) in the follicle. The proprotein convertases are a family of seven known proteins that process TGFbeta ligands and other secreted products to their mature active form. The present study examined the regulation of steady-state levels of Pcsk6 mRNA, which encodes a convertase protein known to process members of the TGFbeta superfamily, during mouse follicular development. Pcsk6 mRNA and protein were expressed in preantral but not cumulus or mural granulosa cells. Pcsk6 mRNA levels in preantral granulosa cells were not regulated by growing oocytes of preantral follicles, but were elevated by FSH. Furthermore, Pcsk6 mRNA in preantral granulosa cells was potently suppressed by factor(s) secreted by fully grown oocytes from antral follicles, in part through SMAD2/3-mediated pathways. Oocytes acquired the ability to suppress the steady-state levels of Pcsk6 mRNA in granulosa cells during the preantral to antral follicle transition. Suppression of Pcsk6 mRNA by oocytes could reflect a change in the mechanism(s) regulating the activity of members of the TGFbeta superfamily.

Polycystic ovary syndrome: a focus on anti-Müllerian hormone levels

Anti-Müllerian hormone (AMH) is a dimeric glycoprotein exclusively produced by the granulosa cells and reflects the size of the growing follicular pool. Serum AMH levels seem to correlate with the development of preantral and small-antral follicles during reproductive life. It has been established that AMH levels are two- to threefold higher in adult women with polycystic ovary syndrome (PCOS) compared with healthy women. This may be related to an increased number of growing follicles that secrete AMH or to an increased per granulosa cell production. Therefore, the understanding of its regulation is important to advance the comprehension of PCOS pathophysiology. Apparently, androgens may play an important role in this regard. Recently, our group documented higher serum levels of AMH in daughters of women with PCOS compared with control girls during three stages of sexual development, early infancy, childhood and peripuberty, suggesting the presence of an increased growing follicular pool in these girls that is established early in development and precedes the onset of clinical hyperandrogenism. In addition, clinical and experimental studies suggest that androgens could also have a role in determining an increased follicular mass during prenatal life, which, during postnatal life, may perpetuate hyperandrogenism. Currently, AMH determination is being progressively used in clinical practice as a marker of ovarian function. In the future, it may become a useful tool to assess ovarian aging and reserve, to diagnose PCOS and to evaluate treatment success.

Changes in serum anti-mullerian hormone level during low-dose recombinant follicular-stimulating hormone therapy for anovulation in polycystic ovary syndrome

CONTEXT

We previously hypothesized that the excess of anti-müllerian hormone (AMH) at the level of selectable follicles could be involved in the follicular arrest of polycystic ovary syndrome (PCOS), mainly through inhibition of FSH effect on aromatase expression.

OBJECTIVE

In this study, we investigated whether a decrease in the serum AMH level was concomitant to the appearance of a dominant follicle induced by administration of mild amounts of exogenous FSH in women with PCOS.

DESIGN

A total of 30 women with PCOS in whom anovulation was resistant to clomiphene citrate received recombinant FSH using the low-dose step-up protocol during only one cycle. Serum levels of estradiol, AMH, LH, FSH, inhibin B, and ultrasound parameters were assessed twice a week until 3 d after the appearance of one or more dominant follicle(s).

RESULTS

The day of dominance (d 0) was defined by the appearance of at least one follicle more than 10 mm growing 2 mm/d. From d -14 before dominance to d +3, the mean serum AMH level and the 2- to 5-mm follicle number at ultrasound declined steadily, although not significantly by ANOVA. Mean AMH relative values (100% being the value at d 0) declined significantly (P = 0.04), from 125 +/- 32% at d -14 to 105 +/- 15% at d -4. Within the same time lag, the mean FSH relative values increased from 91 +/- 17% to 107 +/- 19% (P = 0.013). In the 87 samples obtained from d -14 to -4, absolute values of AMH were positively and negatively associated with those of LH and FSH, respectively, in an independent manner (P = 0.009 and P = 0.03, respectively). In the 55 samples collected at d 0 and +3, they were negatively correlated to those of estradiol (r = -0.272; P < 0.05).

CONCLUSIONS

These data suggest that in anovulatory women with PCOS, gently increasing the serum FSH level reduces the AMH excess, thus relieving the inhibition from the latter on aromatase expression by selectable follicles and allowing the emergence of a dominant follicle.

The use of anti-mullerian hormone in predicting menstrual response after weight loss in overweight women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with reproductive and metabolic abnormalities, specifically menstrual dysfunction and anovulation in conjunction with elevated pre-antral follicle number and arrested follicular maturation. Although anti-müllerian hormone (AMH), an inhibitor of follicle recruitment and maturation, is increased in women with PCOS, the usefulness of circulating AMH levels as a clinical predictor of menstrual response to weight loss in PCOS is not known.

METHODS

Overweight women with PCOS (n = 26, age 32.9 +/- 5.8 yr, weight 98.9 +/- 20.8 kg, body mass index 36.1 +/- 7.0 kg/m(2), mean +/- sd) followed an 8-wk weight loss and 6-month weight maintenance program.

RESULTS

Net reductions in weight (4.6 +/- 4.8 kg), waist circumference (6.0 +/- 5.3 cm), testosterone (0.3 +/- 0.6 nmol/liter), fasting insulin (3.7 +/- 7.6 mU/liter), and the homeostasis model assessment of insulin sensitivity (0.7 +/- 1.3) occurred for all subjects over the entire study duration. Of 26 subjects, 15 (57.7%) responded to the intervention with improvements in menstrual cyclicity (responders). Compared to nonresponders, responders had lower AMH levels at baseline (23.6 +/- 12.0 vs. 37.9 +/- 17.8 pmol/liter; P = 0.021). Only responders had reductions in fasting insulin (6.1 +/- 5.9 mU/liter; P = 0.001) and homeostasis model assessment (1.3 +/- 5.9; P = 0.002) with acute weight loss (wk 0-8). Baseline AMH was most strongly predicted by baseline ghrelin, free testosterone, and insulin (r(2) = 0.528; P = 0.002).

CONCLUSIONS

Overweight women with PCOS who respond to weight loss with menstrual improvements have significantly reduced preweight loss AMH and demonstrate improvements in surrogate measures of insulin resistance with weight loss. Pretreatment AMH is a potential clinical predictor of menstrual improvements with weight loss in PCOS.

Anti-mullerian hormone: clinical relevance in assisted reproductive therapy

Anti-Müllerian Hormone (AMH) is a member of the transforming Growth Factor-B (TGF-B) family synthesized exclusively by the gonads of both sexes. Over the last four years, numerous studies have examined the clinical usefulness of serum AMH levels as a predictor of ovarian response and pregnancy in assisted reproductive technology cycles. Assessment of ovarian reserve in women undergoing assisted reproduction is useful in optimising the treatment protocol. Availability of a reliable measure of ovarian reserve is essential. Currently, serum AMH level seems to be more strongly related to the ovarian reserve and to be a more discriminatory marker of assisted reproductive technology outcome than follicle-stimulating hormone, inhibin B or estradiol, which are more commonly used markers. Our study involving 69 women undergoing a cycle of in vitro fertilisation (IVF) or intracytoplamic sperm injection (ICSI) treatment, confirmed these results. We have shown in this study that AMH is significantly correlated with the number of eggs collected and is of great interest as a negative predictive value for the success of assisted reproductive technology (ART). Further studies are needed to determine AMH cut-off values.

Potential use of biomarkers for analyzing interpopulation and cross-cultural variability in reproductive aging

OBJECTIVE

The aims of this study were (1) to document the extent of variability in physiological aspects of reproductive aging; (2) to outline those areas where more work is needed to expand our knowledge of this variability; (3) to outline available biomarkers that can be used to measure aspects of reproductive aging, such as ovarian reserve and declining hormone levels; and (4) to note potential problems with the use of these biomarkers in cross-cultural settings.

DESIGN

Literature review of English and French publications using PubMed with no date restrictions.

RESULTS

Substantial variability exists in both cultural and physiological aspects of reproductive aging and menopause. However, the extent of variability across populations for many areas of reproductive aging needs better documentation as well as explanation of sources of this variability. Several biomarkers exist for use in cross-cultural research, including ovarian characteristics such as ovarian volume, ovarian reserve, follicular development, and atresia, and levels of hormones such as follicle-stimulating hormone, inhibin B, and anti-mullerian hormone.

CONCLUSION

We urge that further work be undertaken to evaluate and describe variability in physiological aspects of reproductive aging in cross-cultural settings. Some problems exist in the use of biomarkers to record this variability, particularly in remote settings with few logistical resources.

Serum anti-mullerian hormone concentrations are not altered by acute administration of follicle stimulating hormone in polycystic ovary syndrome and normal women

CONTEXT

In the human ovary, expression of anti-Mullerian hormone (AMH) is detected primarily in granulosa cells of preantral and small antral follicles. This finding is consistent with the tight correlation between circulating AMH levels and the number of small antral follicles (2-5 mm) in normal and polycystic ovary syndrome (PCOS) women. In addition, the greater follicle count in PCOS is mirrored by significantly higher serum AMH levels compared with those of normal women. Despite the utility of AMH measurements in evaluating ovarian physiology and function, the regulation of AMH remains poorly understood.

OBJECTIVE

The objective was to determine whether gonadotropins acutely regulate serum AMH in women with PCOS and normal women.

DESIGN

We conducted a prospective study to compare ovarian responses to FSH in two groups of women.

SETTING

The study was conducted in a General Clinical Research Center in a tertiary academic medical center.

PATIENTS

Women with PCOS (age, 18-35 yr; n = 16) and normal ovulatory controls (age, 18-35 yr; n = 11) were recruited for study.

INTERVENTIONS

Serum samples were measured over a 24-h period after an iv injection of recombinant human FSH (150 IU).

MAIN OUTCOME MEASURE(S)

Serum AMH responses after FSH administration were measured.

RESULTS

Basal serum AMH levels were markedly increased in women with PCOS compared with levels observed in normal women. After FSH injection, PCOS women failed to demonstrate changes in circulating AMH over 24 h. A similar lack of alteration in serum AMH was observed in normal women.

CONCLUSIONS

These findings suggest that in PCOS and normal women, acute exposure to FSH does not appear to exert an effect on AMH production.

Increased oocyte degeneration and follicular atresia during the estrous cycle in anti-Müllerian hormone null mice

Anti-Müllerian hormone (AMH) plays an important role in folliculogenesis. AMH null mice display an increased recruitment of primordial follicles. Nevertheless, these mice do not have proportionally more preovulatory follicles. Therefore, AMH null mice provide an interesting genetic model to study the regulation of species-specific number of preovulatory follicles. We studied the follicle pool throughout the estrous cycle at 4 months of age. Analysis of the follicle pool revealed that AMH null mice have an increased and earlier cyclic recruitment of growing follicles despite a blunted FSH surge at estrus. However, FSH levels at estrus were apparently too low to support growth to the preovulatory stage because an increased level of atresia was observed, which neutralized the increased cyclic recruitment. When AMH null mice were subjected to a superovulation scheme, the rise in FSH levels resulted in the rescue of the recruited cohort of growing follicles. Analysis of the follicle pool also revealed that the increased recruitment of primordial follicles in AMH null mice was neutralized by an increased loss of follicles during the transition from small preantral to large preantral follicle. This major loss of follicles was not completely reflected by a corresponding augmentation of atresia but did correspond with an increased number of oocyte remnants observed in AMH null mice. We conclude that a combination of increased oocyte degeneration and increased follicular atresia neutralizes the increased initial and cyclic recruitment in AMH null mice to a normal number of preovulatory follicles.

Expression of anti-Mullerian hormone protein during early follicular development in the primate ovary in vivo is influenced by suppression of gonadotropin secretion and inhibition of vascular endothelial growth factor

Anti-Mullerian hormone (AMH) plays a role during early follicular development and selection. The aim of this study was to determine the pattern of AMH protein expression in the marmoset ovary and to investigate the effects of inhibition of gonadotropins or vascular endothelial growth factor (VEGF) activity on AMH expression in vivo. GnRH antagonist or VEGF Trap, a soluble decoy receptor, was administered on d 0 or 5 of the follicular phase of the cycle, and ovaries were collected at the end of the follicular phase (d 10). AMH protein was expressed in the marmoset ovary in granulosa cells from the primary stage, with the most abundant staining at the preantral and early antral stages. Inhibition of gonadotropin secretion or VEGF activity between d 0-10 of the cycle decreased AMH expression in early preantral follicles (P < 0.01), and AMH expression was decreased in late preantral follicles in the presence of the VEGF Trap (P < 0.01), compared with controls. There was significantly less AMH expression in early antral follicles with both treatments (P < 0.01), and a decrease in the ratio of oocyte-associated/basement-membrane-associated granulosa cell expression of AMH (P < 0.05). When treatments were administered from d 5-10 of the cycle, both VEGF Trap and GnRH antagonist decreased AMH expression in preantral follicles (P < 0.01) but had no significant effect on early antral follicles. In conclusion, VEGF and gonadotropins are involved in the regulation of expression of AMH in the marmoset. This AMH expression may be a marker of abnormal folliculogenesis in the absence of gonadotropin stimulation or functional angiogenesis.

The excess in 2–5 mm follicles seen at ovarian ultrasonography is tightly associated to the follicular arrest of the polycystic ovary syndrome

BACKGROUND

We previously hypothesized that the excess of 2-5 mm follicles seen at ovarian ultrasonography might be involved in the follicular arrest (FA) of polycystic ovary syndrome (PCOS), independently from the main putative contributors of FA, namely hyperandrogenism and hyperinsulinism.

METHODS

A multivariate statistical analysis was applied retrospectively to clinical, biological and ultrasound data that were consecutively collected during 5 years in 457 patients with polycystic ovaries and in 188 age-matched non-hyperandrogenic and regularly cycling controls without PCO at ultrasound.

RESULTS

Stepwise discriminant analysis indicated that in PCOS the 2-5 mm follicle number (FN) gave the strongest correlation to severity of the FA, followed by age and then by fasting insulin level. The other variables [waist circumference (WC), 6-9 mm FN, serum testosterone, FSH, LH and ovarian area] were rejected by the analysis. Multiple linear regression indicated a significant and independent negative relationship between the 2-5 and 6-9 mm FN in the PCOS (r = - 0.186, P < 0.01) and control groups (r = - 0.281, P < 0.01). In PCOS only, the 6-9 mm FN was negatively and independently related to the WC (r = - 0.108, P < 0.05).

CONCLUSIONS

The size of the 2-5 mm follicle pool is an independent and important contributor to the FA of PCOS. This result could be explained by an exaggerated physiological inhibitory effect from this pool on the terminal follicle growth. The metabolic derangement of PCOS that also contributes to the FA would act through a different mechanism.

Sonographic assessment of ovarian reserve. Its correlation with outcome of in vitro fertilization cycles

Ovarian reserve is a crucial factor for normal ovarian response and the achievement of pregnancy after in vitro fertilization (IVF). Recently, the study of morphological markers by means of ultrasonographic counting of antral follicles (AFC) has proved useful. The present prospective study included 327 consecutive IVF patients who had a basal ultrasound scan of their ovarian reserve during the early follicular phase and had a first IVF cycle between 1 and 3 months later. We performed 313 ovum pick-ups with a mean of 11.1 +/- 7.9 oocytes retrieved. The pregnancy rate per aspiration was 34.5%. Clear and significant differences were observed between normal and low response with respect to AFC, follicle-stimulating hormone (FSH) level and age. We also found that AFC correlated negatively and significantly with age, FSH and LH, and positively and also significantly with the total number of follicles, estradiol level and the number of oocytes retrieved. Using receiver operating characteristic curves, the cut-off value of AFC for poor response was 7 follicles. The value of AFC for predicting pregnancy was lower, although patients with AFC of 8 or more follicles obtained significantly higher pregnancy rates. We consider that AFC should be included in the study of the infertile patient.