Context Anti-Müllerian hormone is produced by granulosa cells of small growing follicles in the ovary. Serum AMH levels strongly correlate with the number of growing follicles, and therefore it has received increasing attention as a marker for ovarian reserve. This review summarizes recent findings and limitations in the application of serum AMH in ovarian reserve assessment. Evidence acquisition A PubMed search was conducted to find recent literature on the measurements and use of serum AMH as a marker for ovarian reserve. Evidence synthesis Serum AMH levels are measured to assess the ‘functional ovarian reserve’, a term that is preferred over ‘ovarian reserve’, since AMH levels reflect the pool of growing follicles which potentially can ovulate. Serum AMH levels are used in individualized FSH dosing protocols and may predict the risk of poor response or OHSS, but has limited value in predicting ongoing pregnancy. Serum AMH levels are studied to predict natural or disease-related age of menopause. Studies show that the age-dependent decline rates of AMH vary among women. The generalized implementation of serum AMH measurement has also lead to an increase in diagnostic assays, including automated assays. However, direct comparison of results remains problematic. Conclusion Serum AMH remains the preferred ovarian reserve marker. However, the lack of an international standard for AMH limits comparison between AMH assays. Furthermore, still little is known about endogenous and exogenous factors that influence serum AMH levels, which limits proper interpretation of AMH values in a clinical setting.

Polycystic ovary syndrome (PCOS) is a very heterogeneous disease of which the exact pathophysiological mechanisms remain unknown. In PCOS, serum anti-Müllerian hormone (AMH) levels are significantly increased. AMH is a member of the transforming growth factor b family and is expressed by growing follicles in the ovaries. In PCOS, the transcriptional regulation of AMH and AMHR2 is altered, increasing and prolonging its temporal expression pattern. Moreover, the recently discovered extragonadal effects of AMH suggest that there might be a crosstalk between the ovary-placenta-brain. This review summarizes the recent findings concerning AMH and its role in the etiology of PCOS.

Context Anti-Müllerian hormone (AMH) levels strongly correlate with antral follicles number (TFC) in the ovary. In women with polycystic ovary syndrome (PCOS), this is reflected by significantly increased serum AMH levels. Different assays have been developed to measure AMH. However, little is known about the inter-assay correlation in women with increased AMH levels. Objective To investigate the correlation of AMH values between different AMH assays and with TFC in PCOS patients. Design AMH levels were measured in 1660 PCOS patients, using three different AMH assays: Gen II [Beckman Coulter]; picoAMH [Ansh Labs]; and Elecsys [Roche]. Passing Bablok regression was used to compare assay methods. Spearman’s correlation was used to correlate AMH levels and TFC. Results Strong inter-assay correlations were present over the total range of AMH levels (0.81–0.94). Stratification in subgroups, revealed an AMH level dependent inter-assay correlation with strong inter-assay correlations in the low (<2.80 ng/ml) and high (>7.04 ng/ml) subgroups (0.62–0.86). However, the correlation in the mid AMH subgroup (2.80–7.04 ng/ml) was only moderate (0.28–0.56). A strong correlation was present between the total range of AMH levels and TFC (0.57–0.62). However, in all three AMH subgroups the correlation became moderate at best, independently of assay method (0.11–0.45). Conclusion In conclusion, both the inter-assay correlation and the correlation between AMH level and follicle count depend on the range of serum AMH level. This once more emphasizes the need of a standardization of AMH measurement for an accurate interpretation of AMH in clinical practice.

STUDY QUESTION Do polymorphisms in the anti-Müllerian hormone (AMH) promoter have an effect on AMH levels in patients with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER We have identified a novel AMH promoter polymorphism rs10406324 that is associated with lower serum AMH levels and is suggested to play a role in the mechanism of regulation of AMH gene expression in women. WHAT IS KNOWN ALREADY Follicle number is positively correlated with serum AMH levels, reflected by elevated AMH levels in women with PCOS. In addition, it is suggested that AMH production per follicle is higher in women with PCOS than in normo-ovulatory women, implying an altered regulation of AMH in PCOS. STUDY DESIGN, SIZE, DURATION A discovery cohort of 655 PCOS women of Northern European ancestry and both an internal and external validation PCOS cohort (n = 458 and n = 321, respectively) were included in this study. Summary-level data of an AMH genome-wide association study meta-analysis including 7049 normo-ovulatory women was included as a control cohort. A genetic approach was taken through association analysis and in silico analysis of the associated variants in the AMH promoter. In vitro analysis was performed to investigate the functional mechanisms. PARTICIPANTS/MATERIALS, SETTING, METHODS All common two-allelic single-nucleotide polymorphisms (SNPs) in the region Chr19:2 245 353–2 250 827 bp (Build 37) were selected for the analysis. Linear regression analyses were performed to determine the association between SNPs in the AMH promoter region and serum AMH levels. For the in silico analysis, the webtools ‘HaploReg’ v4.1 for ENCODE prediction weight matrices and ‘atSNP’ were used. In vitro analysis was performed using KK1 cells, a mouse granulosa cell line and COV434 cells, a human granulosa tumor cell line. Cells were transfected with the reference or the variant human AMH promoter reporter construct together with several transcription factors (TFs). Dual-Glo® Luciferase Assay was performed to measure the luciferase activity. MAIN RESULTS AND THE ROLE OF CHANCE Polymorphism rs10406324 was significantly associated with serum AMH levels in all three PCOS cohorts. Carriers of the minor allele G had significantly lower log-transformed serum AMH levels compared to non-carriers (P = 8.58 × 10−8, P = 1.35 × 10−3 and P = 1.24 × 10−3, respectively). This result was validated in a subsequent meta-analysis (P = 3.24 × 10−12). Interestingly, rs10406324 was not associated with follicle count, nor with other clinical traits. Also, in normo-ovulatory women, the minor allele of this variant was associated with lower serum AMH levels (P = 1.04 × 10−5). These findings suggest that polymorphism rs10406324 plays a role in the regulation of AMH expression, irrespective of clinical background. In silico analysis suggested a decreased binding affinity of the TFs steroidogenenic factor 1, estrogen-related receptor alpha and glucocorticoid receptor to the minor allele G variant, however in vitro analysis did not show a difference in promoter activity between the A and G allele. LIMITATIONS, REASONS FOR CAUTION Functional analyses were performed in a mouse and a human granulosa cell line using an AMH promoter reporter construct. This may have limited assessment of the impact of the polymorphism on higher order chromatin structures. Human granulosa cells generated from induced pluripotent stem cells, combined with gene editing, may provide a method to elucidate the exact mechanism behind the decrease in serum AMH levels in carriers of the −210 G allele. We acknowledge that the lack of follicle number in the external validation and the control cohort is a limitation of the paper. Although we observed that the association between rs10406324 and AMH levels was independent of follicle number in our discovery and internal validation PCOS cohorts, we cannot fully rule out that the observed effects on serum AMH levels are, in part, caused by differences in follicle number. WIDER IMPLICATIONS OF THE FINDINGS These results suggest that variations in serum AMH levels are not only caused by differences in follicle number but also by genetic factors. Therefore, the genetic context should be taken into consideration when assessing serum AMH levels in women. This may have clinical consequences when serum AMH levels are used as a marker for the polycystic ovarian morphology phenotype. STUDY FUNDING/COMPETING INTEREST(S) No external funding was used. J.S.E.L. has received consultancy fees from the following companies: Ferring, Roche Diagnostics and Ansh Labs and has received travel reimbursement from Ferring. J.A.V. has received royalties from AMH assays, paid to the institute/lab with no personal financial gain. The other authors declare no competing interests. TRIAL REGISTRATION NUMBER N/A.

No abstract