Characterization of women with elevated antimüllerian hormone levels (AMH): correlation of AMH with polycystic ovarian syndrome phenotypes and assisted reproductive technology outcomes

Pigment epithelium-derived factor expression and role in follicular development

RESEARCH QUESTION

What is the involvement of pigment epithelium-derived factor (PEDF), expressed in granulosa cells, in folliculogenesis?

DESIGN

mRNA expression of PEDF and other key factors [Cyp19, anti-Müllerian hormone receptor (AMHR) and vascular endothelial growth factor (VEGF)] in mice follicles was examined in order to typify the expression of PEDF in growing follicles and in human primary granulosa cells (hpGC), and to follow the interplay between PEDF and the other main players in folliculogenesis: FSH and AMH.

RESULTS

mRNA expression of PEDF increased through folliculogenesis, although the pattern differed from that of the other examined genes, affecting the follicular angiogenic and oxidative balance. In hpGC, prolonged exposure to FSH stimulated the up-regulation of PEDF mRNA. Furthermore, a negative correlation between AMH and PEDF was observed: AMH stimulation reduced the expression of PEDF mRNA and PEDF stimulation reduced the expression of AMHR mRNA.

CONCLUSIONS

Folliculogenesis, an intricate process that requires close dialogue between the oocyte and its supporting granulosa cells, is mediated by various endocrine and paracrine factors. The current findings suggest that PEDF, expressed in granulosa cells, is a pro-folliculogenesis player that interacts with FSH and AMH in the process of follicular growth. However, the mechanism of this process is yet to be determined.

Hypothalamic-Ovarian axis and Adiposity Relationship in Polycystic Ovary Syndrome: Physiopathology and Therapeutic Options for the Management of Metabolic and Inflammatory Aspects

PURPOSE OF REVIEW

The goal of the present review is to address the main adiposity-related alterations in Polycystic Ovary Syndrome (PCOS) focusing on hypothalamic-pituitary-ovarian (H-P-O) axis and to provide an overview of nutraceutical and pharmacological therapeutic strategies.

RECENT FINDINGS

Female reproduction is a complex and delicate interplay between neuroendocrine signals involving the H-P-O axis. Elements that disrupt the balance of these interactions can lead to metabolic and reproductive disorders, such as PCOS. This disorder includes menstrual, metabolic, and biochemical abnormalities as well as hyperandrogenism, oligo-anovulatory menstrual cycles, insulin resistance, and hyperleptinemia which share an inflammatory state with other chronic diseases. Moreover, as in a self-feeding cycle, high androgen levels in PCOS lead to visceral fat deposition, resulting in insulin resistance and hyperinsulinemia, further stimulating ovarian and adrenal androgen production. In fact, regardless of age and BMI, women with PCOS have more adipose tissue and less lean mass than healthy women. Excessive adiposity, especially visceral adiposity, is capable of affecting female reproduction through direct mechanisms compromising the luteal phase, and indirect mechanisms as metabolic alterations able to affect the function of the H-P-O axis. The intricate crosstalk between adiposity, inflammatory status and H-P-O axis function contributes to the main adiposity-related alterations in PCOS, and alongside currently available hormonal treatments, nutraceutical and pharmacological therapeutic strategies can be exploited to treat these alterations, in order to enable a more comprehensive synergistic and tailored treatment.

Age at menarche and risk of ovarian hyperstimulation syndrome in women undergoing IVF/ICSI cycles: a retrospective cohort study

OBJECTIVES

We aimed to explore the association between age at menarche (AAM) and ovarian hyperstimulation syndrome (OHSS) in fresh in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles.

DESIGN

A retrospective cohort study.

SETTING

Data were collected from a large obstetrics and gynaecology hospital in Sichuan, China.

PARTICIPANTS

This study included 17 419 eligible women aged ≤40 years who underwent the first IVF/ICSI cycles from January 2015 to December 2021. Women were divided into three groups according to their AAM: ≤12 years (n=5781), 13-14 years (n=9469) and ≥15 years (n=2169).

RESULTS

The means of age at recruitment and AAM were 30.4 years and 13.1 years, respectively. Restricted cubic spline models suggested that early menarche age increased the risk of OHSS. The multivariable logistic analysis showed that women with menarche age ≤12 years were more likely to suffer from OHSS (OR 1.321, 95% CI 1.113 to 1.567) compared with those aged 13-14 years among the whole cohort. This significant relationship remained in women administered with different ovarian stimulation protocols and gonadotrophin doses. When stratified by female age, this correlation was presented only in patients aged ≤30 years (OR 1.362, 95% CI 1.094 to 1.694). And the mediation analysis showed that the relationship between AAM and OHSS was totally mediated by antral follicle counts (AFC).

CONCLUSION

Menarche age earlier than 12 years may increase the OHSS risk in women aged ≤30 years through the mediation of AFC. More prospective studies are required to verify the results.

Prevention of moderate and severe ovarian hyperstimulation syndrome: a guideline

Ovarian hyperstimulation syndrome is a serious complication associated with assisted reproductive technology. This systematic review aims to identify who is at high risk for developing ovarian hyperstimulation syndrome, along with evidence-based strategies to prevent it and replaces the document of the same name last published in 2016.

Anti-Mullerian Hormone and Fertility Treatment Decisions in Polycystic Ovary Syndrome: A Literature Review

Anti-Mullerian hormone is a robust marker of ovarian reserve and ovarian response in in vitro fertilisation (IVF). However, its role extends beyond improving the safety of IVF by aiding in choosing appropriate protocols and dosing. This review looks at the value of pre-treatment anti-Mullerian hormone (AMH) value in choosing the appropriate modality of treatment and its predictive ability for the outcomes of such treatment. It briefly addresses the factors that may modulate AMH levels and make clinical decision-making challenging.

Diagnostic value of anti-Müllerian hormone combined with androgen-levels in Chinese patients with polycystic ovary syndrome

OBJECTIVE

To establish a cutoff level of AMH which could help for the diagnosis of PCOS, to investigate the predictive value of AMH combined with androgens in Chinese women to diagnose PCOS.

MATERIALS AND METHODS

This is a prospective case control study, 550 women recruited (aged 20-40 years), in which 450 PCOS women recruited according to the Rotterdam criteria and 100 non-PCOS women in the control group were from the women for the pregnancy preparation examination. AMH were measured by the Elecsys AMH Plus immunoassay. Androgens and other sex hormone were measured. The validity of AMH toward the diagnosis of PCOS, or AMH combined with total testosterone, free testosterone, bioavailable testosterone and androstenedione was estimated by receiver operating characteristic (ROC)curves, and correlations between paired variables was estimated by Spearman's rank correlation coefficient.

RESULTS

The cutoff value of AMH in Chinese reproductive-age women with PCOS is 4.64 ng/mL, AUC under the curve is 0.938, with 81.6% sensitivity, and 92.0% specificity. Total testosterone, free testosterone, bioactive testosterone, and androstenedione are significantly higher in women with PCOS of reproductive age than in controls. The combination of AMH and free testosterone resulted in a higher AUC of 94.8%, with higher sensitivity (86.1%) and excellent specificity (90.3%) for the prediction of PCOS.

CONCLUSION

The Elecsys AMH Plus immunoassay, with a cutoff of 4.64 ng/mL, is a robust method for identifying PCOM to aid in PCOS diagnosis. The combination of AMH and free testosterone resulted in a higher AUC of 94.8% for the diagnose of PCOS.

Elevated Anti-Müllerian Hormone as a Prognostic Factor for Poor Outcomes of In Vitro Fertilization in Women with Polycystic Ovary Syndrome

Women with polycystic ovary syndrome (PCOS) tend to have elevated anti-Müllerian hormone (AMH) levels, which appear to correlate with disease severity and pregnancy outcomes. This was a retrospective observational study designed to assess the relationship between circulating AMH levels and in vitro fertilization (IVF) outcomes. The study involved 150 women with PCOS who underwent IVF treatments. The women's IVF cycles were allocated into three subgroups according to AMH levels: 'low' (AMH < 3.7 ng/mL; n = 49), 'middle' (AMH 3.7-7.4 ng/mL; n = 94), and 'high' (AMH > 7.4 ng/mL; n = 56). All pregnancy-related outcomes (positive beta human chorionic gonadotropin (βHCG), clinical pregnancy rate, live birth rate, and cumulative live birth rate) were greater in women's IVF cycles with 'low' AMH when compared to those with 'middle' or 'high' AMH (p < 0.05). AMH levels below 3.7 ng/mL were found to be associated with lower oocyte immaturity rate and better pregnancy outcomes, although baseline AMH was not shown to have any significant predictive power for live birth and cumulative live birth in the multivariable logistic regression analysis after adjusting for possible confounders nor in the ROC analyses. In summary, the current study lays the groundwork to validate high AMH levels as a poor prognostic factor for pregnancy outcomes after IVF in women with PCOS.

Women with PCOS who undergo IVF: a comprehensive review of therapeutic strategies for successful outcomes

Polycystic ovarian syndrome (PCOS) is a widespread syndrome that poses unique challenges and constraints to the field of assisted reproductive technology. This condition is the most common cause of anovulation among infertile couples. Debate exists over the best therapeutic course of action when patients with PCOS proceed to IVF. In this review, we evaluate the best-performing and safest methods of IVF preparation, ovarian stimulation, trigger method for maturation of stimulated egg growth, and planning for embryo transfer. Pre-IVF considerations include being aware of individual AMH and vitamin D levels as well as BMI prior to selecting an ovarian stimulation protocol. Numerous supplements such as myo-inositol complement the benefits of lifestyle change and may enhance IVF performance including oocyte yield and pregnancy rate. Concerning stimulation protocols, antagonist cycles with the judicious use of GnRH agonist trigger, pre-treatment with metformin and vitamin D repletion may help mitigate the accompanied risk of ovarian hyperstimulation syndrome (OHSS). Following ovarian stimulation, PCOS patients typically undergo programmed frozen embryo transfer (FET) cycles which are more conducive for women with irregular cycles, but likely carry a higher risk of hypertensive disorders of pregnancy. However, newer stimulated FET protocols using Letrozole may offer improved outcomes. Overall, patients with PCOS require careful individual tailoring of their IVF cycle to achieve optimal results.

Suitable endometrial thickness on embryo transfer day may reduce ectopic pregnancy rate and improve clinical pregnancy rate

BACKGROUND

This retrospective study aimed to investigate the most suitable endometrial thickness (EMT) on the day of embryo transfer that could reduce ectopic pregnancy rate (EPR) and improve clinical pregnancy rate (CPR) in fresh embryo transfer patients with early follicular phase long-acting regimen.

METHODS

A total of 11,738 IVF/ICSI cycles, comprising 4,489 non-clinical pregnancies, 7,121 intrauterine pregnancies, and 128 ectopic pregnancy cycles after fresh embryo transfer, recorded between September 2017 and December 2020. Clinical pregnancy (CP) and ectopic pregnancy (EP) were the primary outcomes. Multivariate logistic regression was used to calculate the adjusted odds ratio (aOR) and 95% confidence interval (CI) for EP and CP. Patients were divided into three groups based on the EMT (6-10 mm, 11-15 mm, and 16-20 mm). CPR and EPR per millimeter of EMT were drawn into a line chart, and three groups were analyzed by Chi-square test.

RESULTS

After controlling for potential confounders, EMT had a significant effect on CP (aOR = 1.07; 95% CI, 1.05-1.08; P = 0.00) and EP (aOR = 0.88; 95% CI, 0.82-0.94; P = 0.00). With the increase of EMT, CPR increased and EPR decreased. Pearson correlation coefficients were r = 0.708 (P = 0.00) and r =-0.558 (P = 0.03), respectively. Significant differenceswere detected in the CPRs and EPRs (all P = 0.00). The CPR in the 6-10 mm group (54.88%) was significantly lower than that in the 11-15 mm group (64.23%) and the 16-20 mm group (64.40%) (P = 0.00). The EPR in the 6-10 mm group (2.72%) was significantly higher than that in the other two groups (1.60% and 0.97%, P = 0.00). The difference in CPR and EPR between the 11-15 mm group and the 16-20 mm group was not statistically significant, which indicated that EMT ≥ 11 mm simultaneously reduced the EPR and increased the CPR.

CONCLUSIONS

EMT was inversely proportional to EPR and directly proportional to CPR in fresh embryo transfer cycles. The EMT ≥ 11 mm on the day of embryo transfer could simultaneously achieve lower EPR and higher CPR. Accordingly, more attention should be given to the EMT of women who underwent ART treatment.

High anti-Mullerian hormone level is adversely associated with cumulative live birth rates of two embryo transfers after the first initiated cycle in patients with polycystic ovary syndrome

Objective

Anti-Mullerian hormone (AMH) has been recently identified as a potential predictor of live birth rates (LBRs) following assisted reproductive technology (ART) treatment. This study aimed to investigate the association between AMH levels and the outcomes of in vitro fertilization (IVF) in patients with polycystic ovary syndrome (PCOS).

Methods

Patients with PCOS initiating their first ovarian stimulation under the gonadotropin-releasing hormone antagonist protocol at the Guangdong Women and Children Hospital, China, were enrolled from November 2014 to September 2018. A total of 157 patients who underwent fresh embryo transfer (ET) cycles were included in group A, whereas 187 patients who underwent frozen-thawed ET cycles were included in group B. After the failure of the first ET cycle, 94 patients underwent the second ET cycle with frozen-thawed embryos. Of these 94 patients, 52 had failed the first fresh ET cycle (group C) and 42 had failed the first frozen-thawed ET cycle (group D). Successful embryo transfer was defined as live birth. This retrospective cohort study addressed the association between AMH levels and pregnancy outcomes using logistic regression approaches. After adjusting for age, body mass index, antral follicle counts, baseline follicle-stimulating hormone levels and baseline progesterone levels, LBRs were compared among the four groups and the cumulative live birth rate after two embryo transfers (TCLBR) was calculated.

Results

The LBRs showed no differences among the four groups. Higher serum AMH levels were found to be associated with a lower TCLBR [adjusted OR 0.937 (0.888-0.987), P = 0.015]. In patients who underwent the second ET cycle, LBRs were inversely proportional to AMH levels [crude OR 0.904 (0.828-0.986), P = 0.022 versus adjusted OR 0.845 (0.754-0.946), P = 0.004, respectively]. In addition, the LBR was approximately 61%-78% lower in the group with AMH levels of >12 ng/mL [crude OR 0.391 (0.168-0.912), P = 0.030 versus adjusted OR 0.217 (0.074-0.635), P = 0.005, respectively].

Conclusions

Among PCOS patients high AMH level (>12 ng/ml) is found to be associated with low TCLBR and low LBR of the second embryo transfer cycles. The results provide limited clinical inferences and warrant further investigation.

AMH predicts miscarriage in non-PCOS but not in PCOS related infertility ART cycles

BACKGROUND

To study whether AMH levels were associated with miscarriage rates in index ART cycles undergoing fresh autologous transfers in PCOS and non-PCOS related infertility.

METHODS

In the SART CORS database 66,793 index cycles underwent fresh autologous embryo transfers with AMH values reported within the last 1-year between 2014 and 2016. Cycles that resulted in ectopic or heterotopic pregnancies, or were performed for embryo/oocyte banking were excluded. Data were analyzed using Graphpad Prism-9. Odds ratios (OR) were calculated with 95% confidence intervals (CI) along with multivariate regression analysis adjusting for age, body mass index (BMI), and number of embryos transferred. Miscarriage rates were calculated as miscarriage per clinical pregnancies.

RESULTS

Of the total 66,793 cycles, the mean AMH was 3.2 ng/ml and were not associated with increased miscarriage rates for AMH < 1 ng/ml (OR 1.1, CI 0.9-1.4, p = 0.3). Of the 8,490 PCOS patients, the mean AMH was 6.1 ng/ml and were not associated with increased miscarriage rates for AMH < 1 ng/ml (OR 0.8, CI 0.5-1.1, p = 0.2). Of the 58,303 non-PCOS patients, the mean AMH was 2.8 ng/ml and there was a significant difference in miscarriage rates for AMH < 1 ng/ml (OR 1.2, CI 1.1-1.3, p < 0.01). All findings were independent of age, BMI and number of embryos transferred. This statistical significance did not persist at higher thresholds of AMH. The overall miscarriage rate for all cycles, and cycles with and without PCOS were each 16%.

DISCUSSION

The clinical utility of AMH continues to increase as more studies investigate its predictive abilities regarding reproductive outcomes. This study adds clarity to the mixed findings of prior studies that have examined the relationship between AMH and miscarriage in ART cycles. AMH values of the PCOS population are higher than the non-PCOS. The elevated AMH associated with PCOS decreases its utility in predicting miscarriages in IVF cycles as it may be representing the number of developing follicles rather than oocyte quality in the PCOS patient population. The elevated AMH associated with PCOS may have skewed the data; removing this sub-population may have unmasked significance within the non-PCOS associated infertility.

CONCLUSIONS

AMH < 1 ng/mL is an independent predictor of increased miscarriage rate in patients with non-PCOS infertility.

Serum Anti-Mullerian Hormone (AMH) Levels Among Different PCOS Phenotypes and Its Correlation with Clinical, Endocrine, and Metabolic Markers of PCOS

Anti-Mullerian hormone (AMH) is one of the direct indicators of follicular pool but no standard cutoff has been defined for diagnosis of polycystic ovary syndrome (PCOS). The present study evaluated the serum AMH levels among different PCOS phenotypes and correlated the AMH levels with clinical, hormonal, and metabolic parameters among Indian PCOS women. Mean serum AMH was 12.39 ± 5.3ng/mL in PCOS cohort and 3.83 ± 1.5 ng/mL in non-PCOS cohort (P < 0.01). Out of 608 PCOS women, 273 (44.9%) women belonged to phenotype A, 230 (37.8%) women were phenotype D. Phenotypes C and B were 12.17% and 5.10% respectively. Among those with the highest AMH group (AMH>20ng/ml; 8.05%), majority belonged to phenotype A. Menstrual cycle length, serum testosterone, fasting total cholesterol levels, and follicle number per ovary had positive correlation with serum anti-Mullerian levels (P < 0.05). AMH cutoff for the diagnosis of PCOS was calculated as ≥ 6.06 ng/mL on ROC analysis with sensitivity and specificity of 91.45% and 90.71% respectively. The study shows high serum AMH levels in PCOS are associated with worse clinical, endocrinological, and metabolic parameters. These levels may be used to counsel patients regarding treatment response, help in individualized management and prediction of reproductive and long-term metabolic outcomes.

Serum levels of anti-Müllerian hormone influence pregnancy outcomes associated with gonadotropin-releasing hormone antagonist treatment: a retrospective cohort study

As a specific predictor of ovarian reserve, serum anti-Müllerian hormone (AMH) has become an area of intense research interest in the field of assisted reproductive technology. We assessed the relationship between AMH levels and pregnancy outcomes in Chinese patients and investigate the influencing factors of cumulative live birth in patients with high AMH levels. A total of 1379 patients starting their IVF/ICSI cycle were divided into normal (Group A, 1.1-4.0 ng/ml, n = 639) and high (Group B, > 4.0 ng/ml, n = 740) groups by serum AMH levels. Live birth rate (LBR), cumulative live birth rate (CLBR) and cumulative clinical pregnancy rate (CCPR) were also investigated. Compared with Group A, Group B had a significantly higher CLBR (65.80% vs. 43.95%) and CCPR (76.77% vs. 57.14%), respectively. Binomial logistic regression analysis showed that age over 40 years, LH/FSH > 2.5, total Gn dose and Gn duration, and greater than 4000 ng/ml serum E2 levels on HCG day were significantly associated with CLBR in Group B. The AUC value of CLBR averaged 0.664 (ranging from 0.621 to 0.706) (p < 0.001). The patients with high AMH levels had higher CPR, higher LBR, and lower MR with no statistically significant differences, although there were significant improvements in CLBR. Advanced age (> 40 years) still impacted CLBR, even in women with good ovarian reserves. Consequently, it is still recommended that patients over 40 years old with high AMH levels actively receive IVF treatment if they seek to become pregnant. PCOS diagnoses did not influence the CLBR. In summary, this study showed that serum AMH levels could positively predict patient ovarian responses and further affect pregnancy outcomes.

Serum anti-Müllerian hormone levels are associated with perinatal outcomes in women undergoing IVF/ICSI: A multicenter retrospective cohort study

INTRODUCTION

Anti-Müllerian hormone (AMH) level has long been considered as a serum biomarker of ovarian reserve clinically, while emerging data suggest that serum AMH level may also predict pregnancy outcomes. However, whether pregestational serum AMH levels are related to perinatal outcomes among women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles is unknown.

OBJECTIVE

To explore the association between different AMH levels and perinatal outcomes in women with live births in IVF/ICSI.

METHODS

This multicenter retrospective cohort study was conducted among three different provinces in China, from January 2014 to October 2019. A total of 13,763 IVF/ICSI cycles with 5657 live-delivery pregnant women and 6797 newborns were recruited. Participants were categorized into three groups according to the <25th (low), 25 to 75th (average), and >75th (high) percentile of serum AMH concentration. Perinatal outcomes were compared among groups. Subgroup analyses were conducted based on the number of live births.

RESULTS

Among women with singleton deliveries, low and high AMH levels increased the risk of intrahepatic cholestasis of pregnancy (ICP) (aOR1 = 6.02, 95%CI: 2.10-17.22; aOR2 = 3.65, 95%CI:1.32-10.08) and decreased the risk of macrosomia (aOR1 = 0.65, 95%CI:0.48-0.89; aOR2 = 0.72, 95%CI:0.57-0.96), while low AMH reduced the risk of large for gestational age (LGA, aOR=0.74, 95%CI:0.59-0.93) and premature rupture of membrane (PROM, aOR=0.50, 95%CI:0.31-0.79)compared with the average AMH group. In women with multiple deliveries, high AMH levels increased the risks of gestational diabetes mellitus (GDM, aOR=2.40, 95%CI:1.48-3.91) and pregnancy-induced hypertension (PIH, aOR=2.26, 95%CI:1.20-4.22) compared with the average AMH group, while low AMH levels increased the risk of ICP (aOR=14.83, 95%CI:1.92-54.30). However, there was no evidence of differences in preterm birth, congenital anomaly, and other perinatal outcomes among the three groups in both singleton and multiple deliveries.

CONCLUSIONS

Abnormal AMH levels increased the risk of ICP regardless of the number of live births for women undergoing IVF/ICSI, while high AMH levels increased the risks of GDM and PIH in multiple deliveries. However, serum AMH levels were not associated with adverse neonatal outcomes in IVF/ICSI. The underlying mechanism warrants further investigation.

Association between cigarette smoking and ovarian reserve among women seeking fertility care

INTRODUCTION

This study examined the association of smoking with ovarian reserve in a cross-sectional study of 207 women enrolled in the Louisville Tobacco Smoke Exposure, Genetic Susceptibility, and Infertility (LOUSSI) Study and assessed effect modification by NAT2 acetylator phenotype.

METHODS

Information on current smoking status was collected using a structured questionnaire and confirmed by cotinine assay. Serum anti-Müllerian hormone (AMH) levels were used to assess ovarian reserve. Diminished ovarian reserve (DOR) was defined as AMH <1ng/mL. Single nucleotide polymorphisms in the NAT2 gene, which metabolizes toxins found in cigarette smoke, were analyzed to determine NAT2 acetylator status. Linear and logistic regression were used to determine the effects of smoking on ovarian reserve and evaluate effect modification by NAT2. Regression analyses were stratified by polycystic ovary syndrome (PCOS) status and adjusted for age.

RESULTS

Current smoking status, either passive or active as measured by urinary cotinine assay, was not significantly associated with DOR. For dose-response assessed using self-report, the odds of DOR increased significantly for every additional cigarette currently smoked (Odds ratio, OR:1.08; 95% confidence interval, 95%CI:1.01-1.15); additionally, every 1 pack-year increase in lifetime exposure was associated with an increased odds of DOR among women without PCOS (OR: 1.08 95%CI: 0.99-1.18). These trends appear to be driven by the heavy or long-term smokers. Effect modification by NAT2 genotype was not established.

CONCLUSION

A history of heavy smoking may indicate increased risk of diminished ovarian reserve.

Role of anti-Mullerian hormone in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common gynecological endocrine disorders affecting up to 10% of all females in their reproductive age, and its cause of onset is still elusive. A spectrum of recent research reflected diverse associations between increased plasma level of anti-Mullerian hormone (AMH) and different clinical features of PCOS. Since AMH levels reflect the pool of growing follicles that potentially can ovulate, it can be stated that serum AMH levels can be used to assess the “functional ovarian reserve,” rather mentioning it as the “ovarian reserve.” AMH also appears to be a premier endocrine parameter for the assessment of atrophied ovarian follicular pool in response to age of individuals. AMH hinders the follicular development as well as the follicular recruitment and ultimately resulting in follicular arrest which is the key pathophysiologic condition for the onset of PCOS. Furthermore, FSH-induced aromatase activity remains inhibited by AMH that aids emergence of other associated clinical signs of PCOS, such as excess androgen, followed by insulin resistance among the PCOS individuals. Given the versatile association of AMH with PCOS and scarcity in literature explaining the underling mechanisms how AMH relates with PCOS, this review article will discuss the roles of AMH in the pathogenesis of PCOS which may introduce a new era in treatment approach of PCOS.

Anti-Müllerian Hormone and Polycystic Ovary Syndrome in Women and Its Male Equivalent

This article reviews the main findings on anti-Müllerian hormone (AMH) and its involvement in the pathogenesis of polycystic ovary syndrome (PCOS) and its male equivalent. In women, AMH is produced by granulosa cells from the mid-fetal life to menopause and is a reliable indirect marker of ovarian reserve. AMH protects follicles from atresia, inhibits their differentiation in the ovary, and stimulates gonadotrophin-releasing hormone neurons pulsatility. AMH overexpression in women with PCOS likely contributes to the increase of the follicle cohort and of androgen levels, leading to follicular arrest and anovulation. In the male, AMH is synthesized at high levels by Sertoli cells from fetal life to puberty when serum AMH falls to levels similar to those observed in women. AMH is involved in the differentiation of the genital tract during fetal life and plays a role in Sertoli and Leydig cells differentiation and function. Serum AMH is used to assess Sertoli cell function in children with disorders of sex development and various conditions affecting the hypothalamic–pituitary–testicular axis. Although the reproductive function of male relative of women with PCOS has been poorly investigated, adolescents have elevated levels of AMH which could play a detrimental role on their fertility.

Therapeutic Investigation of Standardized Aqueous Methanolic Extract of Bitter Melon (Momordica charantia L.) for Its Potential against Polycystic Ovarian Syndrome in Experimental Animals’ Model: In Vitro and In Vivo Studies

Polycystic ovarian syndrome (PCOS) is an heterogenous, endocrine, metabolic, and multidisciplinary disorder of reproductive-aged females that aggravates insulin resistance, hyperandrogenism, obesity, menstrual irregularities, and infertility. Bitter melon is consumed as vegetable in various parts of the world. The purpose of this study was to provide the rationale for the folkloric uses of bitter melon (Momordica charantia L.) in reproductive abnormalities. HPLC analysis of standardized aqueous methanolic extract of bitter melon revealed the presence of various phytochemicals such as quercetin, gallic acid, benzoic acid, chlorogenic acid, syringic acid, p-coumaric acid, ferulic acid, and cinnamic acid. Twenty-five Swiss albino adult female rats (120–130 g) were acquired and divided into two groups (5 + 20). Letrozole (1 mg/kg p.o.) was used for four weeks to induce PCOS in twenty rats. Disease induction was confirmed by vaginal smear cytology analysis under the microscope. Animals were further divided into four groups, with one group as PCOS group, and the remaining three are treated with standardized extract of bitter melon (500 mg/kg p.o.), bitter melon plus metformin (500 mg/kg p.o.), and metformin alone for the period of next four weeks. After four weeks, the rats were euthanized at diestrus stage. Ovaries of the experimental animals were removed and fixed in 10% buffered formalin, and blood samples were obtained from direct cardiac puncture and stored. Ovaries histopathological analysis showed cystic follicles (9–10) in PCOS group, while, in all the treatment groups, we found developing and mature follicles. Similarly, hormone analysis showed significant (p < 0.001) reduction of LH surge, insulin, and testosterone levels and improvement in FSH levels. Lipid profile and antioxidant enzymes status were also significantly (p < 0.001) improved. In conclusion, the study validates the bitter melon potential as an insulin sensitizer and ovulation enhancer and authenticates its potential in PCOS management.

Increased risk of abortion after frozen-thawed embryo transfer in women with polycystic ovary syndrome phenotypes A and D

Polycystic ovary syndrome (PCOS) is associated with adverse pregnancy outcomes, including an increased risk of abortion, premature delivery, and even neonatal outcomes. After removing the effect of COH on patients, studying the pregnancy outcomes of patients with different PCOS phenotypes after FET may better reflect the impact of different PCOS phenotypes on ART outcomes. Data of 8903 patients who underwent FET between January 2017 and October 2019 were retrospectively collected and evaluated. All patients were divided into a control group and four phenotype groups based on Rotterdam criteria. The main outcomes were pregnancy outcomes after FET. We found significantly higher abortion (P = 0.010) and lower ongoing pregnancy (P = 0.023) rates for women with PCOS phenotypes A and D compared to those in the control group. After adjusting for potential confounders, PCOS phenotypes A and D were associated with an elevated risk of abortion (adjusted OR, 1.476, P = 0.016; adjusted OR, 1.348, P = 0.008, respectively). The results of this study suggest that when performing FET, clinicians should individually manage women with PCOS phenotypes A and D to reduce the rate of abortion and increase the rate of LB, and achieve better pregnancy outcomes.

Impact of increasing antimüllerian hormone level on in vitro fertilization fresh transfer and live birth rate

Objective

The objective of our study was to assess the association between AMH and live birth among women with elevated AMH undergoing first fresh IVF. Serum antimüllerian hormone (AMH) correlates with oocyte yield during in vitro fertilization (IVF). However, there are limited data regarding IVF outcomes in women with elevated AMH levels.

Design

Retrospective cohort study using the Society for Assisted Reproductive Technology Clinical Outcomes Reporting System database from 2012-2014.

Setting

Fertility clinics reporting to Society for Assisted Reproductive Technology.

Patients

First, fresh, autologous IVF cycles with elevated AMH levels (≥5.0 ng/mL). Subanalyses were performed to examine patients with or without polycystic ovary syndrome (PCOS).

Interventions

None.

Main Outcome Measures

Odds of live birth.

Results

Our cohort included 10,615 patients with elevated an AMH level, including 2,707 patients with PCOS only. The adjusted odds of live birth per initiated cycle were significantly lower per each unit increase in the AMH level (odds ratio, 0.97; 95% confidence interval, 0.96-0.98). Increasing AMH level was associated with increased cancellation of fresh transfer (odds ratio, 1.12; 95% confidence interval, 1.10-1.15) up to an AMH level of 12 ng/mL. The decrease in the live birth rate appears to be caused by the increasing incidence of cancellation of fresh transfer because the live birth rate per completed transfer was maintained. Similar trends were observed in the PCOS and non-PCOS subanalyses.

Conclusions

Among patients with AMH levels of ≥5 ng/mL undergoing fresh, autologous IVF, each unit increase in AMH level is associated with a 3% decrease in odds of live birth because of the increased incidence of fresh embryo transfer cancellation.

Proteomics and bioinformatics analysis of follicular fluid from patients with polycystic ovary syndrome

Objectives: Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder with heterogeneous manifestations and complex etiology. We used quantitative proteomics analysis based on mass spectrometry to identify the differences in proteomics profiles for follicular fluid obtained from patients with or without PCOS and explore possible mechanisms underlying PCOS.

Methods: Follicular fluid samples were collected from infertile patients with (n = 9) or without (n = 9) PCOS. Total protein was extracted, quantitatively labeled with a tandem mass tag (TMT), and analyzed using liquid chromatography-mass spectrometry (LC‐MS). TMT-based proteomics and bioinformatics analysis were used to determine the differentially expressed proteins (DEPs) and understand the protein networks. The analysis included protein annotation, unsupervised hierarchical clustering, functional classification, functional enrichment and clustering, and protein-protein interaction analysis. Selected DEPs were confirmed by ELISA, and correlation analysis was performed between these DEPs and the clinical characteristics.

Results: In this study, we have identified 1,216 proteins, including 70 DEPs (32 upregulated proteins, 38 downregulated proteins). Bioinformatics analysis revealed that the inflammatory response, complement and coagulation cascades, activation of the immune response, lipid transport, and regulation of protein metabolic processes were co-enriched in patients with PCOS. Based on ELISA results, insulin-like growth factor binding protein 1 (IGFBP1) and apolipoprotein C2 (APOC2) were differentially expressed between patients with and without PCOS. Follicular IGFBP1 showed a positive correlation with the serum levels of high-density lipoprotein cholesterol (HDL-C) (r = 0.3046, p = 0.0419), but negatively correlated with the serum levels of anti-Müllerian hormone (AMH) (r = –0.2924, p = 0.0354) and triglycerides (r = –0.3177, p = 0.0246). Follicular APOC2 was negatively correlated with the serum apolipoprotein A1 (APOA1) levels (r = 0.4509, p = 0.0002).

Conclusion: Our study identified DEPs in the follicular fluid of patients with PCOS. Inflammatory response, complement and coagulation cascades, activation of the immune response, lipid transport, and regulation of protein metabolic process were deregulated in PCOS, which may play essential roles in the pathogenesis of PCOS.

Prediction model of persistent ovulatory dysfunction in Korean women with polycystic ovary syndrome

AIM

There is no validated tool to predict persistent ovulatory dysfunction after medication with oral contraceptives in women with polycystic ovary syndrome (PCOS), which is the most severe subtype of PCOS. We aimed to build a model to predict persistent ovulatory dysfunction after medication of oral contraceptives in women with PCOS.

METHODS

A total of 286 patients with PCOS were treated with and without oral contraceptives at a tertiary academic medical center. Data were obtained from the electronic medical record system between January 2016 and March 2019. A risk prediction model was developed using multivariable logistic regression. Model 1 was based on age and chief complaints and Model 2 further included predictors evaluated during a clinic visit. Model 3 additionally included laboratory findings.

RESULTS

Of the study population, ovulatory dysfunction was persistent in 117 patients (40.9%). Compared with the simple model (Models 1 and 2), the full prediction model (Model 3) had better Akaike's information criterion (286, 244 vs. 225) and the area under the curve (AUC) increased from 0.74 and 0.79 to 0.84. The full model included 7 covariates measured during the evaluation of PCOS, and two covariates were significant predictors of persistent ovulatory dysfunction in PCOS: age (OR 0.91; 95% CI 0.84-0.97), and anti-Müllerian hormone (OR 1.17; 95% CI 1.09-1.26). This model demonstrated good discrimination (AUC, 0.84) and calibration (Hosmer-Lemeshow goodness of fit test, p = 0.74).

CONCLUSIONS

This prediction model was shown to be a useful method for predicting persistent ovulatory dysfunction after oral contraceptive medication in patients with PCOS.

Association of antimüllerian hormone with polycystic ovarian syndrome phenotypes and pregnancy outcomes of in vitro fertilization cycles with fresh embryo transfer

Objective

The current study was undertaken to investigate the relationship between antimüllerian hormone (AMH) and polycystic ovarian syndrome (PCOS) phenotypes and to determine whether AMH is associated with pregnancy outcomes in infertile women undergoing their first in vitro fertilization (IVF) treatment.

Methods

We performed a retrospective cohort study of 2973 infertile women, including 418 women with PCOS undergoing their first IVF treatment at a private fertility center from January 2014 to March 2018. Women were stratified into three groups using cutoffs defined by the 25^th and 75^th percentiles of the serum AMH level: 746 women had AMH ≤ 2.25 ng/mL; 1486 women had AMH between 2.25 to 5.71 ng/mL; and 741 women had AMH > 5.71 ng/mL. Endocrine characteristics, PCOS phenotypes, stimulation outcomes, pregnancy outcomes were compared among these groups. When there were any statistical differences (P < 0.05) among the three groups, Bonferroni test was performed as post-hoc tests to determine where the statistical differences existed. To assess the relationships between AMH and pregnancy outcomes in total patients and PCOS patients, logistic regression analysis, adjusted for potential confounding covariates, were performed.

Results

Women with high AMH had greater prevalence of hyperandrogenism (HA), polycystic ovarian morphology (PCOM) and amenorrhea than women with low or average AMH. The clinical pregnancy rate were significantly higher in the high-AMH group compared with low- and average-AMH groups (69.9% vs. 58.8% and 64.7% respectively; P < 0.001). The live birth rate was significantly lower in women with AMH ≤ 2.25 ng/mL compared with average- and high-AMH groups (47.6% vs. 55.2 and 59.5% respectively; P < 0.001). However, after controlling for maternal age, oocyte yield, as well as other confounders, AMH was no longer associated with a higher live birth rate (aOR 1.037, 95% CI 0.853–1.261, P = 0.717; aOR 1.099, 95% CI 0.858–1.408, P = 0.455, respectively) and clinical pregnancy rate (aOR 1.064, 95% CI 0.834–1.359, P = 0.617; aOR 1.181, 95% CI 0.875–1.595, P = 0.276, respectively). Moreover, pregnancy outcomes did not differ in PCOS women according to AMH quartiles.

Conclusion

Increased AMH levels associated with PCOS severity and greater ovarian stimulation. However, AMH was not associated with clinical pregnancy rate and live birth rate after controlling for other confounders in women undergoing IVF. Thus, AMH should not be used to alter clinical decisions and exclude patients based on a low or even undetectable AMH value.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04518-0.

Antimullerian Hormone Levels and Association with Abortion and Preterm Delivery in Patients with Polycystic Ovary Syndrome Who Conceived with Assisted Reproductive Techniques

Background

Pregnant PCOS patients were found to suffer from many adverse outcomes of pregnancy. Prediction of the fate of pregnancy and labor in PCOS patients was highly needed. There were recently discovered roles of serum AMH in those patients who were seeking for pregnancy and who were conceiving with assisted reproductive techniques.

Aim

To analyze the predictive roles of measuring serum levels of AMH in patients with PCOS who became pregnant spontaneously or used assisted reproductive techniques regarding abortion and preterm delivery.

Patients and Study Design

A total of 100 females with PCOS were included in the study and they underwent assisted reproductive techniques were included in the study and underwent measurement of AMH levels regularly.

Results

We found that a total of 70 patients had a term delivery, and 30 patients had a preterm delivery. We found no statistically significant differences between both groups regarding their age or body mass index (BMI). We showed that serum AMH levels were higher in the group of PCOS patients who had preterm delivery than in the group of patients with term delivery (p < .0.001).

Conclusions

High serum AMH levels were found to be associated with higher risks of occurrence of preterm labor in patients with PCOS who underwent assisted reproductive techniques. Our results gave a clue to clinicians for better management of the pregnancy process in these patients.

Anti-Müllerian Hormone in Female Reproduction

Anti-Müllerian hormone (AMH), also called Müllerian inhibiting substance, was shown to be synthesized by the ovary in the 1980s. This article reviews the main findings of the past 20 years on the regulation of the expression of AMH and its specific receptor AMHR2 by granulosa cells, the mechanism of action of AMH, the different roles it plays in the reproductive organs, its clinical utility, and its involvement in the principal pathological conditions affecting women. The findings in respect of regulation tell us that AMH and AMHR2 expression is mainly regulated by bone morphogenetic proteins, gonadotropins, and estrogens. It has now been established that AMH regulates the different steps of folliculogenesis and that it has neuroendocrine effects. On the other hand, the importance of serum AMH as a reliable marker of ovarian reserve and as a useful tool in the prediction of the polycystic ovary syndrome (PCOS) and primary ovarian failure has also been acknowledged. Last but not least, a large body of evidence points to the involvement of AMH in the pathogenesis of PCOS.

Decrease in serum anti-Müllerian hormone level per puncture with laparoscopic ovarian drilling using ultrasonically activated device

PURPOSE

To determine the contributing factor in infertility treatment with laparoscopic ovarian drilling (LOD) to the decrease in serum anti-Müllerian hormone (AMH) levels in patients with polycystic ovarian syndrome using an ultrasonically activated device.

METHODS

A retrospective analysis was performed in 60 patients (aged 23-36 years) who received 25-120 punctures in each ovary with LOD treatment from January 2014 to December 2018.

RESULTS

The mean decrease in serum AMH level per puncture with LOD was 0.07 ± 0.04 ng/ml in all 60 patients and 0.08 ± 0.04 ng/ml in patients with ≥10 ng/ml preoperative serum AMH level, which was significantly higher than in those with <10 ng/ml (0.05 ± 0.02 ng/ml). The mean decrease in serum AMH level per puncture in patients with body mass index (BMI) < 18.5 kg/m2 (0.10 ± 0.03 ng/ml) was significantly higher than in those with BMI 18.5-25 kg/m2 (0.07 ± 0.04 ng/ml) and >25 kg/m2 (0.06 ± 0.02 ng/ml).

CONCLUSIONS

The mean decrease in serum AMH levels per puncture with LOD using an ultrasonically activated device depends on the preoperative serum AMH level and BMI of patients.

Infertility and subsequent recurrent miscarriage: Current state of the literature and future considerations for practice and research

Background: Recurrent miscarriage (RM) and infertility are independently associated with adverse pregnancy outcomes, in addition to psychological sequelae. Experiencing pregnancy loss alongside infertility is particularly difficult. International guidance regarding RM is conflicting, and applicability to women with infertility is undetermined. The aim of this study was to: (i) establish if women/couples with a history of infertility are recognised in the literature on the investigation and management of RM, and (ii) determine if the specific needs of women/couples experiencing RM and infertility are ascertained and incorporated into clinical management strategies. Methods: We examined the wide-ranging literature to ascertain what gaps existed. Studies were retrieved through searches of PubMed and Google Scholar up to 21 January 2021 using appropriate controlled vocabulary and combinations of key words. No language or study design restrictions were applied. Results: While women/couples experiencing RM after infertility appear in studies evaluating investigations and proposed treatments, high-quality studies are lacking. Furthermore, they are largely excluded from international clinical guidance and qualitative research. Conclusions: The experiences of women/couples with RM and infertility and their specific care needs within maternity and fertility services are underexplored. It is unclear from current RM guidelines how best to manage and support this complex cohort. Women/couples with infertility and RM are underserved in the literature and in clinical guidance. Further robust studies are warranted to examine pregnancy outcomes, investigations and treatments currently used. Qualitative research is also required to identify their medical and psychological needs to better support this vulnerable group.

Supplementation with human menopausal gonadotropin in the gonadotropin-releasing hormone antagonist cycles of women with high AMH: Pregnancy outcomes and serial hormone levels

OBJECTIVE

To evaluate the value of using both HMG and recombinant FSH (r-FSH) in the GnRH antagonist protocol for women with high AMH.

MATERIALS AND METHODS

This retrospective, single-center cohort study was conducted from January 2013 to December 2018. Of 277 GnRH antagonist IVF/ICSI cycles in women with anti-Mullerian hormone (AMH) ≥5 μg/L, 170 cycles receiving the combination of r-FSH and HMG (77 with HMG added at the beginning of the GnRH antagonist cycle and 93 with HMG added after GnRH antagonist administration) and 107 cycles receiving r-FSH alone were analyzed. The dynamic hormone profiles and embryonic and clinical outcomes of the patients were evaluated.

RESULTS

We observed significantly lower serum LH levels in the r-FSH + HMG groups during ovarian stimulation. The serum estradiol and progesterone levels were lower in the r-FSH + HMG groups on the trigger day. Nevertheless, there were no significant differences with respect to the number of oocytes retrieved, maturation, fertilization, blastocyst formation rate or ovarian hyperstimulation syndrome (OHSS). The implantation and live birth rates were increased in the r-FSH + HMG groups compared with the r-FSH alone group, with no statistical significance.

CONCLUSIONS

HMG for LH supplementation in the GnRH antagonist protocol for patients with high AMH is not significantly superior to r-FSH alone in terms of ovarian response and pregnancy outcome. Nevertheless, HMG supplementation might be appropriate for women with an initially inadequate response to r-FSH or intracycle LH deficiency.

Serum Metabolomics in PCOS Women with Different Body Mass Index

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine and metabolic disorder, affecting 5–10% of women of reproductive age. It results from complex environmental factors, genetic predisposition, hyperinsulinemia, hormonal imbalance, neuroendocrine abnormalities, chronic inflammation, and autoimmune disorders. PCOS impacts menstrual regularities, fertility, and dermatological complications, and may induce metabolic disturbances, diabetes, and coronary heart disease. Comprehensive metabolic profiling of patients with PCOS may be a big step in understanding and treating the disease. The study aimed to search for potential differences in metabolites concentrations among women with PCOS according to different body mass index (BMI) in comparison to healthy controls. We used broad-spectrum targeted metabolomics to evaluate metabolites’ serum concentrations in PCOS patients and compared them with healthy controls. The measurements were performed using high-performance liquid chromatography coupled with the triple quadrupole tandem mass spectrometry technique, which has highly selective multiple reaction monitoring modes. The main differences were found in glycerophospholipid concentrations, with no specific tendency to up-or down-regulation. Insulin resistance and elevated body weight influence acylcarnitine C2 levels more than PCOS itself. Sphingomyelin (SM) C18:1 should be more intensively observed and examined in future studies and maybe serve as one of the PCOS biomarkers. No significant correlations were observed between anthropometric and hormonal parameters and metabolome results.

Does vitamin D supplementation improve ovarian reserve in women with diminished ovarian reserve and vitamin D deficiency: a before-and-after intervention study

OBJECTIVE

Evaluation of vitamin D supplementation on ovarian reserve in women with diminished ovarian reserve and vitamin D deficiency.

METHODS

The study is a before-and-after intervention study that was performed on women with diminished ovarian reserve referred to Shahid Mofteh Clinic in Yasuj, Iran. Eligible women were prescribed vitamin D tablets at a dose of 50,000 units weekly for up to 3 months. Serum levels of vitamin D and AMH were evaluated at the end of 3 months. Significance level was also considered P ≤ 0.05.

RESULTS

Our results have been showed there was a statistically significant difference in vitamin D levels of participants before [12.1(6.5)] and after [26(9.15)] the intervention (P < 0.001). Moreover, there was a statistically significant difference in serum AMH levels of participants before [0.50(0.44)] and after [0.79(0.15)] the intervention (P=0.02 ).

CONCLUSION

In conclusion, the results of the current study support a possible favorable effect of vitamin D on increase AMH expression by acting on the AMH gene promoter. Therefore, it is possible that vitamin D increases AMH levels without changing the antral follicle count/ovarian reserve.

Anti-Müllerian hormone as a qualitative marker - or just quantity?

PURPOSE OF REVIEW

In this review, we will summarize research looking into anti-Müllerian hormone (AMH) as a measure of oocyte quality.

RECENT FINDINGS

AMH is a key factor involved in embryogenesis but also in the development of early follicles. Owing to its relatively small inter and intracycle variability, it has become a widely used method of ovarian reserve testing. In the realm of assisted reproductive technology, it has demonstrated a reliable ability to gauge the number of oocytes obtained during an in-vitro fertilization cycle. For these purposes, AMH is a readily measured quantitative tool. However, its qualitative role is as yet undefined.

SUMMARY

Although levels of this hormone have been associated with fertilization, blastulation, implantation, and clinical pregnancy rates, there is no clear link with live-birth rates. Furthermore, AMH levels do not appear to correspond with risk of fetal trisomy. AMH does show significant predictive value for the risk of premature ovarian insufficiency and time to onset of menopause.

Elevated Anti-Müllerian Hormone Levels in Newborns of Women with Polycystic Ovary Syndrome: a Systematic Review and Meta-analysis Based on Observational Studies

We performed this updated systematic review and meta-analysis to evaluate anti-Müllerian hormone levels (AMH) in newborns of mothers with polycystic ovary syndrome (PCOS) compared with healthy controls. A search of the literature was conducted in the PubMed, MEDLINE, EMBASE, Cochrane Library, CBM, CNKI, WANFANG, and VIP for articles to assess AMH levels in offspring of PCOS and non-PCOS mothers irrespective of language. These databases were searched from their inception to December 7, 2020. The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS) scoring system. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were adopted to calculate the overall estimates with random-effects models. A total of 6 studies with 846 participants were included. The pooled analysis found an increased AMH level in the umbilical cord blood in newborns of PCOS mothers (SMD =0.62, 95% CI [0.28, 0.95]). Subgroup analyses revealed an elevation of AMH concentrations in female neonates, neonates born to American and Asian PCOS mothers. In addition, higher AMH levels were also found in studies diagnosed by the National Institute of Health (NIH) criteria, maternal clinical/biochemical hyperandrogenism, or maternal body mass index (BMI) >30 kg/m². Meta-regression analysis suggested that diagnostic criterion contributed mostly to the high heterogeneity. We demonstrated that AMH levels in neonates born to PCOS mothers were essentially higher, which indicates that AMH may act as an enigmatic role in the pathogenesis of PCOS which inhibits folliculogenesis in the fetal stage.

Response to ovulation induction treatments in women with polycystic ovary syndrome as a function of serum anti-Müllerian hormone levels

PURPOSE

To assess whether anti-Müllerian hormone (AMH) can predict response to ovulation induction (OI) with clomiphene citrate (CC), letrozole (LET), or follicle-stimulating hormone (FSH) in women with polycystic ovary syndrome (PCOS) undergoing OI/intrauterine inseminations (IUI).

METHODS

A total of 738 OI/IUI cycles from 242 patients at an academic center were stratified in three groups by medication: CC (n = 295), LET (n = 180), and FSH (n = 263), in a retrospective fashion. Ovarian response to treatment (RT, development of at least one dominant follicle) was assessed using mixed effects logistic regression models.

RESULTS

Overall, RT cycles had lower AMH levels compared to no-RT cycles (p < 0.001). This finding persisted when analysis was limited to oral agents but attenuated in FSH cycles. For CC and LET cycles, the predicted probability (PProb) for RT decreased as AMH levels increased (PProb (95%CI): 97% (93-100), 79% (70-88), and 75% (61-89); 85% (78-93), 75% (67-83), and 73% (63-86) for AMH pct.: ≤ 25th, ≥ 50th, and ≥ 75th, for CC and LET, respectively)). However, RT was noted in 98.5% of FSH/IUI cycles regardless of AMH. For CC cycles, those with AMH ≥ 75th pct. had lower odds for RT over cycles with AMH < 75th pct. (OR 0.2, 95%CI 0.04-0.8, p = 0.02). Similarly, lower odds for RT were observed in LET cycles with AMH ≥ 75th pct. (0.6, 0.3-1.4, p = 0.25).

CONCLUSION

In PCOS, increasing serum AMH levels are associated with lower probability of RT to oral agents. Our findings constitute a valuable tool for the clinician when counseling PCOS patients and designing a personalized ovulation induction treatment strategy.

Polyphenols: Natural compounds with promising potential in treating polycystic ovary syndrome

Polyphenols are natural compounds used by plants as a defense system against various stresses. In recent years, the importance of these polyhydroxyphenols has extensively increased due to their potent cardioprotection, anti-carcinogenic, anti-oxidant, anti-apoptotic, and anti-inflammatory properties. Therefore, various studies have reported promising results from the studies investigating their efficacy as a therapeutic strategy in various disorders such as human malignancies, cardiovascular diseases, nervous system impairments, diabetes, metabolic syndrome, aging, and inflammation-associated disorders, as well as a polycystic ovarian syndrome (PCOS). Since oxidative stress, hormonal, metabolic, and endocrine disturbances have been shown to play a crucial role in the initiation/progression of PCOS, polyphenols are suggested to be an effective treatment for this disorder. Therefore, this study aimed to discuss the therapeutic potential of multiple polyphenols in PCOS.

Pretreatment antimüllerian hormone levels and outcomes of ovarian stimulation with gonadotropins/intrauterine insemination cycles

OBJECTIVE

To evaluate the association, if any, between serum antimüllerian hormone (AMH) levels and probability of clinical pregnancy and spontaneous abortion (SAB) in the infertility setting.

DESIGN

Retrospective cohort study.

SETTING

Academic fertility center.

PATIENT(S)

A total of 1,861 gonadotropin stimulation/intrauterine insemination cycles stratified by AMH levels into 3 groups: Low, <25th percentile (<0.7 ng/mL); Middle, ≥25th and <75th percentile (0.7-4.4 ng/mL); and High, ≥75th percentile (≥4.5 ng/mL).

INTERVENTION(S)

Intrauterine insemination after stimulation with gonadotropins.

MAIN OUTCOME MEASURE(S)

Cumulative probability of clinical pregnancy over a maximum of 3 and/or 6 cycles and SAB incidence risk rate (IRR). The Kaplan-Meier failure function (log rank test), Cox proportional hazards models, and multilevel mixed-effects Poisson regression models were performed to compare outcomes among the AMH groups.

RESULT(S)

Overall, in both unadjusted and adjusted models, the probability of achieving a clinical pregnancy was higher in the Middle and High AMH groups compared with that in the Low AMH group, both over 3 (hazard ratios [95% confidence interval], 1.55 [1.05-2.29] and 1.85 [1.22-2.81], respectively) and 6 (1.71 [1.17-2.48] and 2.12 [1.42-3.16], respectively) cycles. In the unadjusted models, the SAB IRR was higher among the Low AMH group (IRR [95% confidence interval], 2.17 (1.11-4.24]), with the relationship persisting after adjusting for age (1.83 [0.93-3.60]). When the SAB IRR were calculated separately for the subpopulations with and without polycystic ovary syndrome, a similar relationship was noted among the latter in the unadjusted (1.94 [0.97-3.88]) and adjusted (1.74 [0.86-3.49]) analyses.

CONCLUSION(S)

In women undergoing gonadotropin stimulation/intrauterine insemination, AMH appears to affect the probability of achieving a clinical pregnancy. A possible negative impact, independent of age, on the risk of SAB was also suggested.

Low risk of OHSS with follitropin delta use in women with different polycystic ovary syndrome phenotypes: a retrospective case series

BACKGROUND

To explore the efficacy of follitropin delta in ovarian stimulation of patients with the Rotterdam ESHRE/ASRM 2003 phenotypes of polycystic ovarian syndrome (PCOS) using a retrospective case series with an electronic file search in a reproductive medicine clinic.

CASE PRESENTATION

Seventy-four patients with PCOS undergoing ovarian stimulation according to the individualized dosing algorithm of follitropin delta for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI)/oocyte freezing were included. Follitropin delta resulted in a high number of pre-ovulatory follicles at the end of stimulation as expected in patients with PCOS. There was a large number of oocytes retrieved with an acceptable percentage of metaphase II (MII) oocytes. There were no cases of moderate or severe OHSS across all phenotypes.

CONCLUSION

Follitropin delta, using the individualized dosing algorithm, appears to be a safe method of ovarian stimulation with a low risk of OHSS in PCOS patients without sacrificing successful stimulation outcomes.

High Serum Anti-Müllerian Hormone Concentrations Are Associated With Poor Pregnancy Outcome in Fresh IVF/ICSI Cycle but Not Cumulative Live Birth Rate in PCOS Patients

OBJECTIVE

To investigate the association between baseline serum Anti-Müllerian hormone (AMH) levels and IVF/ICSI outcomes in women with polycystic ovary syndrome (PCOS).

DESIGN

Retrospective study.

SETTING

Reproductive medicine center in a hospital.

POPULATION

2436 PCOS patients (Rotterdam criteria) who underwent their first fresh IVF/ICSI cycles were divided into three groups on the basis of the <25th (Group 1, n=611), 25 to 75th (Group 2, n=1216), or >75th (Group 3, n=609) percentile of baseline serum AMH level.

INTERVENTIONS

Baseline serum AMH levels measured on the 2-3 days of spontaneous menstrual cycle before IVF/ICSI treatment.

MAIN OUTCOME MEASURES

Live birth rate (LBR), cumulative live birth rate (CLBR), clinical pregnancy rate (CPR), and normal fertilization rate (FR).

RESULTS

The LBR, CPR, and FR were significantly increased in Group 1 than Group 2 and Group 3, however, CLBR was similar between the three groups. The LBR were 46.6%, 40.5%, and 39.4% in Group 1, Group 2, and Group 3 respectively. The CPR were 53.0%, 47.0%, and 45.5%, respectively. The FR was highest in Group 1 (61.7%, P<0.05), but there was no uniform reverse trend with the AMH level. CLBR were 68.7%, 70.4%, and 71.3%, respectively. Although women in Group 1 were older (p < 0.05) and had higher body mass index (BMI) (p < 0.05), binomial logistic regression analysis used age, BMI, FSH, and AMH as independent variables indicated that only AMH was significantly associated with LBR and CPR. Nevertheless, binomial logistic regression analysis used age, BMI, FSH, AMH, and the number of retrieved oocytes as independent variables indicated that only the number of retrieved oocytes was significantly correlated with CLBR. After stratifying by age, the negative relationship between baseline AMH level and LBR and CPR remained only in the patients <30 years old.

CONCLUSIONS

Higher baseline AMH level in PCOS women resulted in lower LBR, CPR, and FR but did not influence CLBR.

ANGPTL4 Expression in Ovarian Granulosa Cells Is Associated With Polycystic Ovary Syndrome

OBJECTIVES

This study aims to characterize the expression of ANGPTL4 in ovarian granulosa cells (GCs) and its association with polycystic ovary syndrome (PCOS).

METHODS

This study included 104 PCOS patients and 112 women in control group undergoing in vitro fertilization-embryo transfer (IVF-ET) from the reproductive hospital affiliated with Shandong University from 2019 to 2021. By reverse transcription and real-time quantitative (RT-q) PCR, the mRNA expression of ANGPTL4 in GCs was assessed, and clinical information for these patients were then reviewed and analyzed.

RESULTS

The RT-qPCR results showed that ANGPTL4 expression in the control group was significantly lower than that in the PCOS group (p = 0.000) and had positive association with AMH (r = 0.211), HOMA-IR (r = 0.174), LDL/HDL (r = 0.176), ApoB/ApoAI (r = 0.155), and TC/HDL (r = 0.189). Additionally, the high expression of ANGPTL4 in the ovarian granulosa cells might be an independent predictor in PCOS (OR: 3.345; 95% CI: 1.951-5.734) with a close contact with incidence of PCOS (AUC: 0.704; 95% CI: 0.633-0.774, p < 0.001).

CONCLUSIONS

Our study revealed higher ANGPTL4 expression in ovarian GCs with PCOS. Its association with glucose and lipid metabolism showed that ANGPTL4 might play an important role in PCOS metabolism and pathogenesis.

Polycystic ovary syndrome, amenorrhea and the diagnostic role of anti-Müllerian hormone

The differential diagnosis of anovulatory disorders is actually based on serum gonadotrophin and estradiol levels. However, several other markers have been proposed. The purpose of this review was to underline the role of anti-Müllerian hormone (AMH) as a possible marker in differential diagnosis of the anovulatory diseases and its use as a predictive marker of prognosis. In this article we discuss clinical and experimental evidences actually existing in literature and we suggest new potential clinical application of AMH.

The association between anti-Müllerian hormone and vitamin 25(OH)D serum levels and polycystic ovarian syndrome in adolescent females

BACKGROUND

High anti-Müllerian hormone (AMH) levels and 25-hydroxyvitamin D [25(OH)D] deficiency have been associated with polycystic ovarian syndrome (PCOS) in adult women, and implicated in its pathogenesis. Herein we determined if the level of both AMH and 25(OH)D are altered in adolescent females with clinical features of PCOS.

METHODS

This is a cross-sectional study utilizing a retrospective chart review of 128 patients aged 12-20 referred to an academic adolescent gynecology and endocrinology clinic for an evaluation of suspected PCOS. Unadjusted comparisons of AMH and 25(OH)D distributions between subjects with and without PCOS were performed using the Wilcoxon Rank Sum test. Quantile regression was used to compare the median AMH and 25(OH)D between subject groups; adjusting for race, ethnicity, BMI, insurance type, age, and season when bloodwork was performed.

RESULTS

Seventy-four subjects were classified as having PCOS by meeting ≥2 of the three Rotterdam diagnostic criteria, and 47 subjects met only one Rotterdam diagnostic criteria, and were used as the comparative non-PCOS group. There were statistically significant unadjusted differences in median levels of AMH and 25(OH)D. In the adjusted analyses, median AMH was significantly higher in the PCOS group compared to the non-PCOS group (+ 2.39 ng/mL, 95% CI 0.43, 4.35, p = 0.018); 25(OH)D was significantly lower in the PCOS group (- 9.01 ng/mL, 95% CI -14.49, - 3.53 p = 0.001). In our sample, adolescents in both groups had insufficient 25(OH)D level (22 ng/mL) and elevated BMI (32.2 kg/m2).

CONCLUSIONS

Adolescents with PCOS display high levels of AMH and low 25(OH)D levels. Since traditional clinical markers of PCOS may be physiologic in adolescents, AMH and 25(OH)D may be used as surrogate markers of PCOS risk in adolescents.

A sensitive HPLC-DMS/MS/MS method for multiplex analysis of androgens in human serum without derivatization and its application to PCOS patients

Both classical androgens and 11-oxygenated androgens play important roles in polycystic ovarian syndrome (PCOS). Therefore, high-quality measurements of androgens are very important. In the present study, a highly sensitive and specific method was developed and validated for the simultaneous determination of three classical androgens and five 11-oxygenated androgens in human serum, using a high- performance liquid chromatography-differential mobility spectrometry tandem mass spectrometry (HPLC-DMS/MS/MS). Serum samples were extracted with the mixture of ethyl acetate/tert-butyl methyl ether (1/1, v/v) prior to analysis with the HPLC-DMS/MS/MS system. Stable isotopes were used as the internal standards. Separation was performed on a Poroshell SB C18 column (150 × 2.1 mm, 2.7 μm), with a differential mobility spectrometry (DMS) component, which was used to enhance the resolution. The gradient mobile phase consisted of acetonitrile and ammonium formate buffer with 0.1 % formic acid in both solvents. The sensitivity of the majority of the androgens was improved following addition of the DMS component. Under the optimal conditions, the trace amount of the target androgens in the serum was quantified accurately. The lower limit of quantification of the different analytes ranged from 0.05 to 0.2 ng/mL. The method was validated prior to its application to the assay of the clinical samples.

Role of anti-Müllerian hormone and testosterone in follicular growth: a cross-sectional study

BACKGROUND

Anti-Müllerian hormone (AMH) is now considered the best serum biomarker of ovarian reserve, while basal sex hormones are classic markers used for assessing ovarian reserve. The interaction between AMH and sex hormones are complicated and not sufficiently addressed. In this study, we took diminished ovarian reserve (DOR) and polycystic ovarian syndrome (PCOS) as two extremes of ovarian reserve (deficient and excessive respectively) to investigate the role of AMH and sex hormones in follicular growth.

METHODS

A retrospective cross-sectional survey was performed. The patients assessed AMH and basal sex hormones in the Second Hospital of Zhejiang University from April 2016 to March 2019 were involved in this study. Serum AMH and sex hormone concentrations were tested with electrochemiluminescence method. Stepwise linear regression and binary logistic regression was used to determine the predictors of AMH level and to explore the involved factors determining DOR and PCOS.

RESULTS

In the present study, we found that age and follicle-stimulating hormone (FSH) were main negative correlation factors, and luteinizing hormone (LH) and testosterone (T) were main positive factors of AMH. In DOR group, age, FSH and estradiol (E₂) increased and T decreased, while in PCOS group, LH and T increased. Binary logistic regression found that age, weight, FSH, E₂, and T were the significant factors which independently predicted the likelihood of DOR, and that age, body mass index (BMI), AMH, LH, and T predicted the likelihood of PCOS.

CONCLUSIONS

Our study demonstrated that age, FSH, and T were factors that most closely correlated with AMH level, and T was involved in both DOR and PCOS. Since DOR and PCOS are manifested with insufficient AMH and excessive AMH respectively, it is suggested that total testosterone correlated with AMH closely and plays an important role in follicular growth. More attention should be given to testosterone level during controlled ovarian hyperstimulation (COH) process.

The Association between Vitamin D and Anti-Müllerian Hormone: A Systematic Review and Meta-Analysis

Accumulating evidence from animal and human studies indicates a role for vitamin D in female reproductive physiology, and numerous clinical studies have suggested its potential benefit for various aspects of human reproduction. Anti-Müllerian hormone (AMH) is an ovarian biomarker that plays an important role in folliculogenesis. It is the most sensitive ovarian reserve marker and is widely used clinically in reproductive medicine. While initial studies have suggested that vitamin D may be associated with ovarian reserve markers, including AMH, evidence has been conflicting. Currently, there is considerable debate in the field whether vitamin D has the capacity to influence ovarian reserve, as indicated by the AMH level. The current systematic review aims to evaluate and summarize the available evidence regarding the relationship between vitamin D and AMH. In total, 18 observational studies and 6 interventional studies were included in this systematic review. Cross-sectional studies have reported largely discrepant findings regarding an association between serum vitamin D and AMH levels, which are likely due to the heterogeneity in study populations, as well as the apparently complex relationship that may exist between vitamin D and AMH. However, meta-analysis of interventional studies performed herein that examined the effects of vitamin D supplementation on serum AMH levels indicates a cause-effect relationship between vitamin D and AMH, the direction of which appears to depend on a woman’s ovulatory status. Serum AMH was significantly decreased following vitamin D supplementation in polycystic ovarian syndrome (PCOS) women (standardized mean difference (SMD) −0.53, 95% CI −0.91 to −0.15, p < 0.007), while it was significantly increased following vitamin D supplementation in ovulatory women without PCOS (SMD 0.49, 95% CI 0.17 to 0.80, p = 0.003). In conclusion, the results of this systematic review demonstrate that the relationship between vitamin D and AMH is a complex one, and large, randomized trials of vitamin D supplementation focusing on different vitamin D status ranges are necessary to gain more insight into the nature of this relationship and the potential benefit of vitamin D to female reproduction in general.

Diminished ovarian reserve and poor response to stimulation in patients <38 years old: a quantitative but not qualitative reduction in performance

STUDY QUESTION

Do infertile women aged <38 years with quantitative evidence of diminished ovarian reserve and/or poor response to stimulation also exhibit poor oocyte quality as measured by blastulation rates, aneuploidy rates, and live birth rates?

SUMMARY ANSWER

Young women with evidence of accelerated follicular depletion, either by precycle ovarian reserve testing or postcycle evidence of low oocyte yield, exhibit equivalent blastulation rates, aneuploidy rates and live birth rates per euploid embryo transfer as age-matched controls with normal precycle and postcycle parameters.

WHAT IS KNOWN ALREADY

Previous studies are conflicted as to whether women with evidence of diminished ovarian reserve and/or poor ovarian response are also at increased risk of exhibiting evidence of poor oocyte quality. Most prior studies have failed to adequately control for the confounding effect of female age on typical markers of oocyte quality in poor responders. The rate of follicular depletion occurs at around 38 years on average; thus, evidence of quantitative depletion before this would indicate a premature diminution of ovarian reserve and allow evaluation of whether markers of oocyte quality are tied to quantitative markers.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study at a single center between 2012 and 2016. This time frame was specifically chosen as all embryos were cultured to the blastocyst stage at this center during the study period (no cleavage stage transfers were performed). Two comparisons were made: precycle assessment of ovarian reserve (based on anti-mullerian hormone (AMH) level) and postcycle oocyte yield results. For each comparison, patients in <10th percentile were compared to patients in the interquartile range (IQR) with respect to blastulation rate, aneuploidy rate and live birth rate. A mixed effects model was created to control for female age (in the <38 year old range) and correlation among oocytes from a given cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

For the precycle blastulation analysis, only patients with AMH data available were included (345 patients with AMH in the <10th percentile versus 1758 patients with AMH in the 25th to 75th percentile (IQR)). To compare aneuploidy rates, the subset of these patients who pursued preimplantation genetic testing for aneuploidy (PGT-A) was then analyzed (124 patients in the <10th percentile versus 782 patients in the IQR). For the postcycle blastulation analysis, all patients who proceeded to retrieval (whether or not they also had AMH data available) were included (535 patients with oocyte yield in the <10th percentile versus 2675 patients in the IQR). To compare aneuploidy rates, the subset of these patients who pursued PGT-A was then analyzed (156 patients in the <10th percentile versus 1100 patients in the IQR).

MAIN RESULTS AND THE ROLE OF CHANCE

The adjusted odds of a given fertilized oocyte developing to a blastocyst, being aneuploid or leading to a live birth after euploid transfer were no different if the oocyte was retrieved from a cycle with ovarian reserve parameters or oocyte yield in the <10th percentile compared to an oocyte retrieved in a cycle with those parameters in the 25-75th percentile. An AMH level in the <10th percentile did more commonly result in cycle cancellation prior to retrieval and after retrieval prior to transfer due to global arrest of embryos.

LIMITATIONS, REASONS FOR CAUTION

The timing of retrieval in patients with fewer oocytes may be more optimal given the greater ability to discern the overall maturity of the cohort, thus enhancing performance per retrieved oocyte. Analyses included only first cycles. Subsequent adjustment of protocol due to prior performance may mean that some patients in the <10th percentile for oocyte yield are actually better prognosis patients than their first cycle indicates. Data on whether or not patients were on oral contraceptives at time that AMH level drawn was not available. Other unknown biases are also likely to be present given retrospective nature of the study.

WIDER IMPLICATIONS OF THE FINDINGS

While young women with evidence of quantitative depletion of ovarian reserve have lower live birth rates per stimulation cycle, this not attributable to poor oocyte quality because the blastulation rate per fertilized oocyte and live birth rate per embryo transfer are equivalent to that in women with normal quantitative markers of ovarian reserve. Thus, the pathophysiology mediating a premature quantitative decline in ovarian reserve appears different than that which mediates markers of oocyte quality, such as aneuploidy. Young poor responders may use this information to help guide embryo accumulation strategies when considering their family building plans.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

High serum Antimullerian hormone levels are associated with lower live birth rates in women with polycystic ovarian syndrome undergoing assisted reproductive technology

INTRODUCTION

Antimullerian hormone (AMH) strongly correlates with ovarian reserve and response to controlled ovarian stimulation. Emerging data suggests that serum AMH level may also predict ART outcomes. However, AMH is characteristically elevated in PCOS women and it is unknown whether it may predict live birth outcomes in this population.

METHODS

This was a retrospective cohort study of 184 PCOS women (Rotterdam criteria) who underwent their first fresh IVF/ICSI cycle. Women were divided into 3 groups according to the <25th (low), 25 to 75th (average), or > 75th (high) percentile of serum AMH concentration. Cycle stimulation parameters and reproductive outcomes were compared between groups.

RESULTS

Women in the low serum AMH group were older than those in the average or high AMH (p < 0.05), and required greater gonadotropin dose for stimulation compared to the high AMH group (p < 0.05). Women with high AMH had greater testosterone level compared to women in the low or average AMH groups. No differences were noted between groups in terms of maximal E2, oocytes retrieved and fertilization rate. However, low serum AMH women had significantly greater live birth rates (p < 0.05) and showed a trend towards greater clinical pregnancy rates compared to women in the average and high AMH groups (p = 0.09). The significant association of AMH with live birth rate remained after adjusting for age, BMI, day of transfer and number of embryos transferred.

CONCLUSIONS

In PCOS women, elevated AMH concentrations are associated with hyperandrogenism and lower live birth rates.

Improving the accuracy and efficacy of diagnosing polycystic ovary syndrome by integrating metabolomics with clinical characteristics: study protocol for a randomized controlled trial

Background

Polycystic ovary syndrome (PCOS) is a complex endocrine syndrome with poorly understood mechanisms. To provide patients with PCOS with individualized therapy, it is critical to precisely diagnose the phenotypes of the disease. However, the criteria for diagnosing the different phenotypes are mostly based on symptoms, physical examination and laboratory results. This study aims to compare the accuracy and efficacy of diagnosing PCOS by integrating metabolomic markers with common clinical characteristics.

Methods

This is a prospective, multicenter, analyst-blinded, randomized controlled trial. Participants will be grouped into (1) people without PCOS (healthy control group), (2) patients diagnosed with PCOS based on clinical indices (experimental group 1), and (3) patients diagnosed with PCOS based on metabolomic indices (experimental group 2). A total of 276 participants, including 60 healthy people and 216 patients with PCOS, will be recruited. The 216 patients with PCOS will be randomly assigned to the two experimental groups in a 1:1 ratio, and each group will receive a different 6-month treatment. The primary outcome for the experimental groups will be the effect of PCOS treatment.

Discussion

The results of this trial should help to determine whether using metabolomic indices is more accurate and effective than using clinical characteristics in diagnosing the phenotypes of PCOS. The results could provide a solid foundation for the accurate diagnosis of different PCOS subgroups and for future research on individualized PCOS therapy.

Trial registration

Chinese Clinical Trial Registry, ID: ChiCTR-INR-1800016346. Registered 26 May 2018.

Use of AMH in the Differential Diagnosis of Anovulatory Disorders Including PCOS

Since the historical use of gonadotrophin and estradiol levels to define the different anovulatory disorders has shown some limitations, the use of other markers such as anti-müllerian hormone (AMH) has been proposed. This review addresses the role of AMH in the differential diagnosis of anovulatory disorders, especially focusing on its value in the prognostic characterization of their severity. Current limitations and future clinical applications are discussed.