Axel P. N. Themmen

Antimüllerian hormone serum levels: a putative marker for ovarian aging

OBJECTIVE To investigate whether serum concentrations of antimüllerian hormone may be used as a marker for ovarian aging. DESIGN Longitudinal observational study. SETTING Academic research center. PATIENTS Forty-one normo-ovulatory premenopausal women and 13 healthy postmenopausal women. MAIN OUTCOME MEASURE(S) Concentrations of serum antimüllerian hormone (assessed on two occasions 2.6 +/- 1.7 years apart), FSH, inhibin B, and estradiol and number of ovarian follicles on ultrasonography. RESULT(S) Concentrations of antimüllerian hormone decreased significantly over time (median value, 2.1 microg/L [range, 0.1-7.4 microg/L] at visit 1 vs. 1.3 microg/L [range, 0.0-5.0 microg/L] at visit 2), whereas the number of antral follicles and levels of FSH and inhibin B did not change. During visits 1 and 2, concentrations of antimüllerian hormone correlated with age (r = -.40, P=.01 and r = -.57, P<.001, respectively); number of antral follicles (r =.66, P<.001 and r =.71, P<.001); and, to a lesser extent, with FSH level (r = -.29, P=.07 and r = -.37, P<.05) but not with inhibin B levels. CONCLUSION(S) Serum concentrations of antimüllerian hormone decreased over time in young normo-ovulatory women, whereas other markers associated with ovarian aging did not change. Concentrations of antimüllerian hormone correlate with the number of antral follicles and age and less strongly with FSH level. Concentrations of antimüllerian hormone may be a novel marker for ovarian aging.

Control of primordial follicle recruitment by anti-Mullerian hormone in the mouse ovary

The dimeric glycoprotein anti-Mullerian hormone (AMH) is a mem- ber of the transforming growth factor-b superfamily of growth and differentiation factors. During male fetal sex differentiation, AMH is produced by Sertoli cells and induces degeneration of the Mullerian ducts, which form the anlagen of part of the internal female genital system. In females, AMH is produced by the ovary, but only postna- tally. The function of AMH in the ovary is, however, still unknown. Female AMH null mice were reported to be fertile, with normal litter size, but this does not exclude a more subtle function for ovarian AMH. To investigate the function of AMH in the ovary, the complete follicle population was determined in AMH null mice, in mice het- erozygous for the AMH null mutation, and in wild-type mice of dif- ferent ages: 25 days, 4 months, and 13 months. In the present study we found that ovaries of 25-day- and 4-month-old AMH null females, compared to those of wild-type females, contain more preantral and small antral follicles. In addition, in 4- and 13-month-old AMH null females, smaller numbers of primordial follicles were found. Actually, in 13-month-old AMH null females, almost no primordial follicles could be detected, coinciding with a reduced number of preantral and small antral follicles in these females. In almost all females heterozy- gous for the AMH null mutation the number of follicles fell in between the numbers found in wild-type and AMH null females. In 4-month- old AMH null females serum inhibin levels were higher and FSH levels were lower compared to those in wild-type females. In contrast, inhibin levels were lower in 13-month-old AMH null females, and FSH levels were unchanged compared to those in wild-type females. Furthermore, the weight of the ovaries was twice as high in the 4-month-old AMH null females as in age-matched wild-type females. We conclude that AMH plays an important role in primordial follicle recruitment, such that more primordial follicles are recruited in AMH null mice than in wild-type mice; the mice heterozygous for the AMH null mutation take an in-between position. Consequently, the ovaries of AMH null females and those of females heterozygous for the AMH null mutation will show a relatively early depletion of their stock of primordial follicles. The female AMH null mouse may thus provide a useful model to study regulation of primordial follicle recruitment and the relation between follicular dynamics and ovarian aging. (Endocrinology 140: 5789 -5796, 1999)

Anti-Müllerian Hormone Inhibits Initiation of Primordial Follicle Growth in the Mouse Ovary

Recruitment of primordial follicles is essential for female fer- tility; however, the exact mechanisms regulating this process are largely unknown. Earlier studies using anti-Mullerian hormone (AMH)-deficient mice suggested that AMH is in- volved in the regulation of primordial follicle recruitment. We tested this hypothesis in a neonatal ovary culture system, in which ovaries from 2-d-old C57Bl/6J mice were cultured for 2 or 4di n theabsence or presence of AMH. Ovaries from 2-d-old mice contain multiple primordial follicles, some naked oo- cytes, and no follicles at later stages of development. We ob- served that in the cultured ovaries, either nontreated or AMH- treated, follicular development progressed to the same extent as in in vivo ovaries of comparable age, confirming the validity of our culture system. However, in the presence of AMH, cul- tured ovaries contained 40% fewer growing follicles compared with control ovaries. A similar reduction was found after 4 d of culture. Consistent with these findings, we noted lower inhibin -subunit expression in AMH-treated ovaries com- pared with untreated ovaries. In contrast, expression of AMH ligand type II receptor and the expression of oocyte markers growth and differentiation factor 9 and zona pellucida protein 3 were not influenced by AMH. Based on the results, we suggest that AMH inhibits initia- tion of primordial follicle growth and therefore functions as an inhibitory growth factor in the ovary during these early stages of folliculogenesis. (Endocrinology 143: 1076 -1084, 2002)

ANTI-MULLERIAN HORMONE ATTENUATES THE EFFECTS OF FSH ON FOLLICLE DEVELOPMENT IN THE MOUSE OVARY

Although ovarian follicle growth is under the influence of many growth factors and hormones of which FSH remains one of the most prominent regulators. Therefore, factors affecting the sensitivity of ovarian follicles to FSH are also important for follicle growth. The aim of the present study was to investigate whether anti-Mullerian hormone (AMH) has an inhibitory effect on follicle growth by decreasing the sensitivity of ovarian follicles to FSH. Furthermore, the combined action of AMH and FSH on ovarian follicle development was examined. Three different experiments were performed. Using an in vitro follicle culture system it was shown that FSH-stimulated preantral follicle growth is attenuated in the presence of AMH. This observation was confirmed by an in vivo experiment showing that in immature AMH-deficient females, more follicles start to grow under the influence of exogenous FSH than in their wild-type littermates. In a third experiment, examination of the follicle population of 4-month-old wild-ty...

Anti-Müllerian hormone and folliculogenesis

This paper reviews the role of anti-Müllerian hormone, a member of the TGF(beta) family signaling through a BMP-like pathway, in the ovary. In vivo and in vitro studies showed that AMH has an inhibitory effect on primordial follicle recruitment and it decreases the sensitivity of follicles for the FSH-dependent selection for dominance. Besides its functional role in the ovary, AMH serum level serves as an excellent candidate marker of ovarian reserve.

Anti-Müllerian hormone is a promising predictor for the occurrence of the menopausal transition.

Objective: Age at menopause and age at the start of the preceding period of cycle irregularity (menopausal transition) show considerable individual variation. In this study we explored several markers for their ability to predict the occurrence of the transition to menopause. Design: A group of 81 normal women between 25 and 46 years of age visited the clinic two times (at T1 and T2) with an average interval of 4 years. All had a regular menstrual cycle pattern at T1. At T1, anti-müllerian hormone (AMH), follicle-stimulating hormone (FSH), inhibin B and estradiol (E2) were measured, and an antral follicle count (AFC) was made during the early follicular phase. At T2, information regarding cycle length and variability was obtained. Menopause transition was defined as a mean cycle length of less than 21 days or more than 35 days or as a mean cycle length of 21 to 35 days, but with the next cycle not predictable within 7 days during the last half year. A logistic regression analysis was performed, with the outcome measure as menopause transition. The area under the receiver operating curve (ROCAUC) was calculated as a measure of predictive accuracy. Results: In 14 volunteers, the cycle had become irregular at T2. Compared with women with a regular cycle at T2, these women were significantly older (median 44.7 vs 39.8 y, P < 0.001) and differed significantly in AFC, AMH, FSH, and inhibin B levels assessed at T1. All parameters with the exception of E2 were significantly associated with the occurrence of cycle irregularity; AMH, AFC, and age had the highest predictive accuracy (ROCAUC 0.87, 0.80, and 0.82, respectively). After adjusting for age, only AMH and inhibin B were significantly associated with cycle irregularity. Inclusion of inhibin B and age to AMH in a multivariable model improved the predictive accuracy (ROCAUC 0.92). Conclusions: The novel marker AMH is a promising predictor for the occurrence of menopausal transition within 4 years. Adding inhibin B improved the prediction. Therefore, AMH alone or in combination with inhibin B may well prove a useful indicator for the reproductive status of an individual woman.

Anti-mullerian hormone predicts menopause: a long-term follow-up study in normoovulatory women

CONTEXT It has been hypothesized that a fixed interval exists between age at natural sterility and age at menopause. Both events show considerable individual variability, with a range of 20 yr. Correct prediction of age at menopause could open avenues of individualized prevention of age-related infertility and other menopause-related conditions, like cardiovascular disease and breast carcinoma. OBJECTIVE The aim of this study was to explore the ability of ovarian reserve tests to predict age at menopause. DESIGN AND SETTING We conducted a long-term follow-up study at an academic hospital. PARTICIPANTS A total of 257 normoovulatory women (age, 21-46 yr) were derived from three cohorts with highly comparable selection criteria. INTERVENTIONS Anti-Müllerian hormone (AMH), antral follicle count, and FSH were assessed at time 1 (T1). At time 2 (T2), approximately 11 yr later, cycle status (strictly regular, menopausal transition, or postmenopause) and age at menopause were inventoried. MAIN OUTCOME MEASURES Accuracy of the ovarian reserve tests in predicting time to menopause was assessed by Cox regression, and a nomogram was constructed for the relationship between age-specific AMH concentrations at T1 and age at menopause. RESULTS A total of 48 (19%) women had reached postmenopause at T2. Age, AMH, and antral follicle count at T1 were significantly related with time to menopause (P < 0.001) and showed a good percentage of correct predictions (C-statistic, 0.87, 0.86, and 0.84, respectively). After adjusting for age, only AMH added to this prediction (C-statistic, 0.90). From the constructed nomogram, it appeared that the normal distribution of age at menopause will shift considerably, depending on the individual age-specific AMH level. CONCLUSIONS AMH is highly predictive for timing of menopause. Using age and AMH, the age range in which menopause will subsequently occur can be individually calculated.

Antral Follicle Count Reliably Predicts Number of Morphologically Healthy Oocytes and Follicles in Ovaries of Young Adult Cattle

Abstract Methods to predict numbers of healthy oocytes in the ovaries of young adults could have important diagnostic relevance in family planning and animal agriculture. We have observed that peak antral follicle count (AFC) determined by serial ovarian ultrasonography during follicular waves is very highly reproducible within individual young adult cattle, despite 7-fold variation among animals. Herein, we tested the hypothesis that AFC is positively associated with the number of morphologically healthy oocytes and follicles in ovaries and with serum concentrations of anti-Müllerian hormone (AMH), an indirect marker for number of healthy follicles and oocytes in ovaries. In the present study, age-matched young adult cattle (12–18 mo old) were subjected to serial ultrasonography to identify animals with a consistently high (≥25 follicles that were ≥3 mm in diameter) or low (≤15 follicles) AFC during follicular waves. Differences in serum AMH concentrations, ovary weight, and number of morphologically healthy and atretic follicles and oocytes were determined. The phenotypic classifications of cattle based on AFC during follicular waves or AMH concentrations both predict reliably the relative number of morphologically healthy follicles and oocytes in ovaries of age-matched young adult cattle.

Anti-Müllerian hormone and its role in ovarian function.

Anti-Müllerian hormone (AMH) is expressed after birth in the ovary in the granulosa cells of healthy, small growing follicles. We have shown that AMH affects two important regulatory steps during folliculogenesis. At initial recruitment, AMH inhibits recruitment of primordial follicles into the growing pool, while at cyclic recruitment AMH lowers the FSH-sensitivity of follicles. In these ways, AMH plays an important role in regulation of ovarian follicle growth. AMH serum level is a strong candidate marker for ovarian reserve in women. In normo-ovulatory women, AMH serum levels correlated strongly with the number of antral follicles. In addition, AMH is a strong predictor for the number of oocytes retrieved in patients undergoing IVF treatment. The convenience of determination and its relative stable expression during the menstrual cycle indicate that further validation of the use of serum AMH is recommended as a clinical measure of ovarian reserve.

An inactivating mutation of the luteinizing hormone receptor causes amenorrhea in a 46,XX female.

Hypergonadotropic hypogonadism is characterized by decreased gonadal function due to the inability of the gonads to respond to pituitary gonadotropins. Hypergonadotropic hypogonadism in females has many causes, among which are ovarian dysgenesis and abnormalities of the ovarian receptors for the pituitary gonadotropins. We evaluated a woman who presented with amenorrhea due to hypergonadotropic hypogonadism, but who had structurally normal ovaries. She is a sister of two previously identified 46,XY male pseudohermaphrodites with Leydig cell hypoplasia. Injection of hCG did not cause any change in plasma levels of estradiol or progesterone, suggesting complete ovarian resistance to LH. Analysis of the DNA sequence of the LH receptor gene revealed that the patient is homozygous for the same single base change as her two brothers. This mutation causes substitution of an alanine residue by a proline at position 593. In vitro analysis of the mutant LH receptor in cultured human embryonic kidney 293 cells documented that the receptor is unable to stimulate adenylyl cyclase in response to hCG. Plasma levels of estradiol and progesterone were low, whereas LH and FSH levels were increased. On histological analysis of the ovary, follicles were seen at all developmental stages. Nonetheless, primary amenorrhea had been present for 5 yr, and repeated measurements of plasma estradiol and progesterone indicate that ovulation does not occur. These results document the existence of inherited LH resistance as a cause of primary amenorrhea in women. The combined clinical and molecular observations are consistent with previous experimental data suggesting that in humans, LH is necessary for ovulation but follicular maturation can occur in the presence of FSH alone.