Anti-Müllerian hormone (AMH) levels reflect a woman's ovarian reserve, acting as a key predictor for reproductive lifespan and IVF outcomes. Research shows AMH is the best endocrine marker for assessing age-related fertility decline, predicting poor ovarian response (≤4 oocytes) with 72-97% sensitivity and hyper-response (>15 oocytes) with 69-93% sensitivity during IVF. Women with PCOS typically have 2-4 times higher AMH levels due to excessive follicle development, while new standardized ELISA tests improve clinical reliability though international standards are still needed.

Understanding Anti-Müllerian Hormone: Your Fertility and Ovarian Health Guide

Table of Contents

• Introduction: Why AMH Matters
• Study Methods: How Researchers Investigated AMH
• Anti-Müllerian Hormone in Ovarian Physiology
• Methods for Measuring AMH in Blood
• AMH as a Marker for Ovarian Reserve
• AMH and In Vitro Fertilization (IVF)
• AMH and Polycystic Ovary Syndrome (PCOS)
• Clinical Implications for Patients
• Study Limitations
• Patient Recommendations
• Source Information

Introduction: Why AMH Matters

Over the past 50 years, women in Western societies have been starting families later due to increased education and career participation. Female fertility naturally declines from the early twenties because of decreasing ovarian reserve - the quantity and quality of remaining eggs. This decline varies significantly between women, making it challenging to predict individual reproductive lifespans.

Anti-Müllerian hormone (AMH) has emerged as a crucial biomarker for ovarian reserve. Produced by developing follicles in the ovaries, AMH levels reflect the pool of remaining eggs. Unlike other fertility hormones, AMH shows minimal monthly fluctuation and isn't significantly affected by pregnancy, birth control, or body weight. This stability makes it particularly valuable for assessing fertility potential.

AMH testing provides critical information for:

• Predicting reproductive lifespan and timing of menopause
• Assessing ovarian response before IVF treatment
• Diagnosing conditions like PCOS (polycystic ovary syndrome)
• Identifying early ovarian aging

Study Methods: How Researchers Investigated AMH

Researchers conducted a comprehensive review of scientific literature up to November 2011 using the PubMed database. They searched for studies containing the term "anti-Müllerian hormone" combined with related keywords like "blood," "diagnostic use," and "ovarian reserve."

This search yielded 235 publications, of which 96 were excluded because they weren't in English, didn't involve humans, or weren't relevant to female fertility. The remaining 139 publications were evaluated for quality and relevance to these key themes:

1. AMH's role in female infertility
2. Ovarian physiology
3. Ovarian reserve assessment
4. IVF applications
5. PCOS diagnosis

For IVF outcome analysis, researchers specifically included studies that:

• Defined poor ovarian response as ≤4 eggs retrieved
• Provided measurable data (sensitivity, specificity, cut-off values)
• Used established AMH assays (IBC or DSL)

Ultimately, 80 high-quality publications formed the basis of this review, including 12 prospective and 7 retrospective cohort studies, plus one case-control study examining AMH's predictive value for IVF outcomes.

Anti-Müllerian Hormone in Ovarian Physiology

AMH plays crucial roles in ovarian function and egg development. During fetal development, the ovaries form about one million primordial follicles (immature egg sacs). Throughout a woman's life, these follicles gradually leave the resting pool to start growing - a continuous process called initial recruitment.

AMH is produced by:

• Primary follicles (early growth stage)
• Secondary follicles
• Preantral follicles (before fluid-filled space develops)
• Small antral follicles (up to 4mm diameter)

Production peaks in preantral and small antral follicles, then decreases as follicles mature. AMH has two critical functions:

1. Slows initial recruitment from the primordial follicle pool
2. Reduces sensitivity to FSH (follicle-stimulating hormone) during cyclic recruitment (the monthly selection of a dominant egg)

Research in AMH-deficient mice shows they exhaust their egg supply prematurely, confirming AMH's protective role in preserving ovarian reserve. This hormone essentially acts as a "brake" preventing too many follicles from developing at once.

Methods for Measuring AMH in Blood

AMH is measured through blood tests using specialized assays. Two main commercial tests have been available:

• IBC (Immunotech-Beckman-Coulter) assay
• DSL (Diagnostic System Laboratories) assay

While results from these tests correlate well, absolute values differ significantly - DSL results are typically about four times lower than IBC results (1 ng/mL = 7.14 pmol/L). This variation complicates direct comparisons between studies using different tests.

Important developments:

• Beckman Coulter introduced a second-generation AMH Gen II assay
• No international standard exists yet, limiting widespread clinical use
• Automated testing platforms are under development

When interpreting your AMH results, note that values can be reported in either ng/mL or pmol/L. Always confirm which unit and assay method your lab uses.

AMH as a Marker for Ovarian Reserve

Ovarian reserve describes both the quantity and quality of a woman's remaining eggs. AMH levels directly reflect the number of developing follicles, which correlates with the size of the primordial follicle pool. Key findings:

• AMH levels are barely detectable at birth
• Levels rise significantly at puberty
• Gradual decline occurs throughout reproductive years
• AMH becomes undetectable at menopause

Compared to other ovarian reserve markers, AMH offers distinct advantages:

Studies following women for up to 11 years confirm AMH predicts age-related fertility decline better than other markers. AMH levels can also estimate when menopause will begin with reasonable accuracy, though more research is needed to confirm its predictive power for natural conception.

AMH and In Vitro Fertilization (IVF)

AMH testing before IVF helps predict treatment response and optimize medication protocols. Research shows:

Predicting Poor Response (≤4 eggs retrieved)

Studies involving 1026 patients found AMH predicts poor response with:

• Sensitivity: 72-97% (correctly identifies poor responders)
• Specificity: 41-93% (correctly identifies normal responders)
• Positive Predictive Value (PPV): 30-79%
• Negative Predictive Value (NPV): 90-98%

Cut-off values ranged from 1.43 to 14.0 pmol/L depending on the study and assay used. The high NPV means normal AMH levels reliably indicate normal ovarian response.

Predicting Pregnancy Success

AMH's ability to predict live birth is more limited:

• Sensitivity: 50-86%
• Specificity: 28-82%
• PPV: 31-84%

Age significantly impacts this relationship. Pregnancy rates correlate with AMH only for women aged 34-41. Younger women (under 34) with low AMH can still conceive, while women over 42 have reduced success regardless of AMH.

Predicting Hyper-Response and OHSS Risk

High AMH predicts excessive response to fertility drugs and ovarian hyperstimulation syndrome (OHSS) risk:

• Sensitivity: 69-93%
• Specificity: 67-81%
• PPV: 22-65%
• NPV: 94-99%

Cut-off values ranged from 15.0 to 34.5 pmol/L. The very high NPV means low AMH reliably indicates low OHSS risk.

AMH and Polycystic Ovary Syndrome (PCOS)

Women with polycystic ovary syndrome (PCOS) - affecting 5-10% of females - typically show elevated AMH levels due to:

1. Excessive numbers of preantral and small antral follicles (2-3 times normal)
2. Increased AMH production per granulosa cell

PCOS patients have AMH levels 2-4 times higher than women without PCOS. This excess AMH contributes to PCOS symptoms by:

• Disrupting follicle development
• Preventing dominant follicle selection
• Contributing to irregular ovulation

AMH testing shows promise for PCOS diagnosis, especially when ultrasound isn't conclusive or for adolescents where ultrasound criteria don't apply. However, standardized diagnostic cut-offs haven't been established.

Clinical Implications for Patients

AMH testing provides actionable insights for different patient groups:

For Women Planning Pregnancy

AMH helps estimate remaining reproductive years. Women with low AMH for their age may consider:

• Earlier family planning
• Egg freezing if delaying pregnancy

For IVF Patients

AMH predicts response to ovarian stimulation:

• Low AMH (<7 pmol/L): Higher risk of poor response (≤4 eggs). Medication protocols may be adjusted, but pregnancy is still possible especially in younger women.
• High AMH (>15-25 pmol/L): Increased OHSS risk. Doctors may use lower medication doses and special protocols.

For PCOS Patients

Elevated AMH supports PCOS diagnosis and explains ovulation difficulties. AMH monitoring may help track treatment response.

Study Limitations

While AMH shows great promise, important limitations exist:

• Cannot reliably predict natural conception ability
• Limited accuracy for live birth prediction in IVF (only moderate correlation)
• Lack of standardized international reference ranges
• Different assays (IBC vs. DSL) yield different absolute values
• No established AMH thresholds for PCOS diagnosis
• Limited data on AMH's relationship to egg quality (vs. quantity)

Most studies are observational - randomized controlled trials are needed to confirm whether AMH-guided treatment improves outcomes.

Patient Recommendations

Based on current evidence:

1. Interpret AMH with your age: Low AMH is more concerning after 35, while high AMH under 35 may indicate PCOS
2. Request assay details: Know which test (IBC or DSL) was used and the units (pmol/L or ng/mL)
3. Combine with other tests: FSH, estradiol, and antral follicle count provide complementary information
4. Discuss with specialists: Fertility doctors can explain your specific results in context
5. For IVF patients: Ask how your AMH might influence medication protocols
6. For high AMH: Be aware of OHSS symptoms if pursuing IVF
7. Remember: AMH doesn't define fertility potential - many women with low AMH conceive naturally

Source Information

Original Article Title: The role of anti-Müllerian hormone in female fertility and infertility – an overview
Authors: Anna Garcia-Alix Grynnerup, Anette Lindhard, Steen Sørensen
Publication: Acta Obstetricia et Gynecologica Scandinavica, Volume 91, Issue 11, pages 1252-1260
Publication Date: October 2012
DOI: 10.1111/j.1600-0412.2012.01471.x
This patient-friendly article is based on peer-reviewed research