Anti-Mullerian Hormone (AMH)
AMH is the best blood test for ovarian reserve — how many eggs remain. Produced by small ovarian follicles, it reflects the remaining egg pool. Can be tested any day of cycle (unlike FSH). High AMH = more eggs (but also PCOS pattern). Low AMH = fewer eggs, potentially shorter fertility window. Predicts IVF response excellently. Key insight: AMH measures quantity, NOT quality — egg quality depends on age regardless of AMH. Women in late 20s-30s planning to delay childbearing benefit from knowing baseline.
Anti-Müllerian Hormone (AMH) is the best blood test available for assessing ovarian reserve — an estimate of how many eggs remain in a woman’s ovaries. Produced by cells in developing ovarian follicles, AMH levels reflect the size of the remaining egg pool. Unlike other fertility hormones that fluctuate through the menstrual cycle, AMH remains relatively stable, making it convenient to test any time.
Why does this matter? AMH provides crucial information for family planning and fertility treatment. Women with low AMH may have fewer reproductive years remaining and might consider earlier pregnancy attempts or egg freezing. Women with high AMH may have more time but should also be evaluated for PCOS, which elevates AMH. For IVF, AMH predicts how many eggs can be retrieved, helping doctors optimize treatment protocols. Understanding your AMH level empowers informed decisions about reproductive timing.
Key Benefits of Testing
AMH testing provides the most reliable single blood test for ovarian reserve. Unlike FSH, which must be tested on specific cycle days and fluctuates monthly, AMH is stable throughout the cycle and between cycles, making it practical and reproducible.
For fertility treatment, AMH predicts ovarian response to stimulation medications. This helps doctors select appropriate medication doses and set realistic expectations. Women with low AMH may need higher doses and should expect fewer eggs. Women with high AMH respond vigorously and need careful monitoring to avoid ovarian hyperstimulation syndrome.
What Does This Test Measure?
The AMH test measures the concentration of Anti-Müllerian Hormone in blood. AMH is a protein hormone produced by granulosa cells in small developing ovarian follicles — specifically, pre-antral and small antral follicles. These are follicles that haven’t yet been recruited for ovulation but represent the pool from which future eggs will come.
What AMH Reflects
AMH correlates with the number of small follicles in the ovaries, which in turn reflects the remaining primordial follicle pool — your egg reserve. Women are born with all the eggs they’ll ever have (about 1-2 million), and this number declines throughout life. By puberty, around 300,000-400,000 remain. Only about 400-500 will actually ovulate during reproductive years; the rest gradually undergo atresia (natural cell death). AMH gives a window into how many are left.
AMH Through Life
AMH levels follow a predictable pattern. They’re low in childhood, rise after puberty, peak in the early to mid-20s, then gradually decline with age as the egg pool diminishes. The rate of decline varies between individuals — some women maintain higher AMH into their late 30s, while others see earlier decline. By menopause, AMH becomes undetectable because no developing follicles remain.
AMH Stability
Unlike FSH, estradiol, and LH, which fluctuate dramatically through the menstrual cycle, AMH remains relatively constant. This stability is a major advantage — AMH can be tested on any day of the cycle, making scheduling convenient. Minor fluctuations can occur, but they’re small enough that single measurements are clinically useful.
What AMH Does NOT Tell You
AMH indicates quantity of eggs, not quality. Egg quality declines with age independent of AMH. A 40-year-old with good AMH still has older eggs with higher chromosomal abnormality rates than a 30-year-old with similar AMH. AMH also doesn’t predict natural fertility — women with low AMH can conceive naturally if they’re still ovulating. It predicts response to IVF stimulation better than it predicts natural conception.
Why This Test Matters
Fertility Planning
Assesses reproductive timeline. AMH helps estimate how many reproductive years might remain. Low AMH in your early 30s suggests less time than average and might prompt earlier pregnancy attempts. Normal or high AMH provides some reassurance but isn’t a guarantee — age still affects egg quality.
Informs egg freezing decisions. Women considering fertility preservation can use AMH to understand their current egg supply. Lower AMH might encourage proceeding sooner; very low AMH might affect the number of eggs retrievable.
IVF and Fertility Treatment
Predicts ovarian response. AMH is the best predictor of how many eggs will be retrieved during IVF. This helps fertility specialists choose medication protocols — higher doses for low AMH, careful doses for high AMH to prevent complications.
Sets realistic expectations. Knowing AMH helps couples understand likely IVF outcomes. Very low AMH predicts fewer eggs and may indicate consideration of donor eggs. Very high AMH may mean many eggs but requires vigilance for ovarian hyperstimulation syndrome.
Diagnosing Conditions
Supports PCOS diagnosis. Women with polycystic ovary syndrome often have elevated AMH because they have many small follicles. High AMH, especially with other PCOS features (irregular periods, elevated androgens, polycystic ovaries on ultrasound), supports the diagnosis.
Confirms premature ovarian insufficiency. Very low or undetectable AMH in a woman under 40 with elevated FSH and menstrual irregularities confirms premature ovarian insufficiency (POI).
Value of Knowing Your AMH Early
Many women don’t discover they have diminished ovarian reserve until they’re already trying to conceive and struggling. Testing AMH proactively — before actively trying to get pregnant — provides information when it’s most actionable. A woman in her late 20s or early 30s who learns her AMH is low has time to make decisions about timing or fertility preservation. Waiting until fertility problems emerge may mean fewer options.
This doesn’t mean everyone needs AMH testing — but women with family history of early menopause, those who may delay childbearing, or those simply wanting information for planning can benefit from knowing their baseline.
What Can Affect AMH Levels?
Causes of High AMH
- Polycystic ovary syndrome (PCOS) — many small follicles producing AMH
- Younger age — AMH peaks in early 20s
- Granulosa cell tumors of the ovary (rare)
- Higher ovarian reserve (natural variation)
Causes of Low AMH
- Advancing age — natural decline of ovarian reserve
- Premature ovarian insufficiency (POI)
- Previous ovarian surgery — removal of ovarian tissue reduces follicle pool
- Chemotherapy or radiation affecting ovaries
- Endometriosis — may reduce AMH, especially after surgery
- Autoimmune conditions affecting ovaries
- Smoking — associated with lower AMH and earlier menopause
- Genetic factors — family history of early menopause
Factors That Don’t Significantly Affect AMH
AMH is not significantly affected by hormonal contraceptives in most studies, though some research suggests minor suppression with long-term use. Pregnancy suppresses AMH, which recovers after delivery. Short-term factors like stress, diet, or menstrual cycle day have minimal impact, which is why AMH is so convenient to test.
When Should You Get Tested?
Fertility planning: Women considering future pregnancy who want to understand their ovarian reserve, especially those who may delay childbearing.
Before fertility treatment: AMH is routinely tested before IVF or other assisted reproduction to guide treatment protocols.
Difficulty conceiving: As part of infertility evaluation to assess ovarian reserve alongside other tests.
Family history of early menopause: Women whose mothers or sisters experienced menopause before 45 may want to check their own ovarian reserve.
Considering egg freezing: AMH helps predict how many eggs might be retrieved and whether multiple cycles might be needed.
Irregular periods with PCOS features: AMH helps evaluate for PCOS when combined with other findings.
Suspected premature ovarian insufficiency: Symptoms suggesting early menopause in women under 40.
After ovarian surgery, chemotherapy, or radiation: To assess remaining ovarian function.
Understanding Your Results
AMH interpretation depends on age and clinical context. What’s normal for a 25-year-old differs from what’s normal for a 38-year-old.
Age-Appropriate Interpretation
AMH naturally declines with age. A level that’s “low” for a 28-year-old might be “normal” for a 40-year-old. Results should be interpreted relative to age-specific expectations. Your doctor or the lab report should provide age-adjusted context.
Low AMH
Low AMH for age indicates diminished ovarian reserve — fewer eggs remaining than typical. This doesn’t mean infertility — women with low AMH can and do conceive naturally. However, it suggests less time remaining and potentially reduced response to fertility medications. It may prompt consideration of earlier pregnancy attempts or fertility preservation.
Normal AMH
Age-appropriate AMH provides reassurance about ovarian reserve but isn’t a fertility guarantee. Egg quality, tubal function, uterine health, partner factors, and other variables also matter. Normal AMH is encouraging but doesn’t eliminate age-related fertility decline.
High AMH
Higher-than-expected AMH may simply reflect good ovarian reserve. However, very high AMH — especially with irregular periods or other symptoms — raises suspicion for PCOS. High AMH also predicts vigorous response to IVF medications, requiring careful monitoring to avoid ovarian hyperstimulation syndrome.
Undetectable AMH
Very low or undetectable AMH indicates very few or no remaining follicles. In young women, this suggests premature ovarian insufficiency. In women approaching typical menopause age, it may indicate imminent menopause. Undetectable AMH generally predicts poor response to IVF stimulation.
What to Do About Abnormal Results
For Low AMH
Don’t panic. Low AMH indicates quantity, not quality, and doesn’t mean you can’t conceive. Many women with low AMH have successful pregnancies.
Consider timeline. If pregnancy is desired, lower AMH may suggest not waiting too long. Discussing timing with a reproductive endocrinologist can help.
Evaluate fertility preservation. If not ready for pregnancy, egg freezing becomes more urgent with lower reserve. Consultation with a fertility specialist can clarify options.
Optimize IVF protocols. If pursuing IVF, low AMH guides protocol selection. Higher medication doses, specialized protocols, and realistic expectations about egg numbers are appropriate.
Consider repeat testing. Single low values can occasionally be lab error or natural variation. Confirming with a repeat test may be reasonable.
For High AMH
Evaluate for PCOS. Very high AMH with irregular periods, acne, hirsutism, or obesity warrants PCOS evaluation. Ultrasound may show polycystic-appearing ovaries.
Monitor during fertility treatment. High AMH predicts strong response to stimulation medications. Lower doses and careful monitoring prevent ovarian hyperstimulation syndrome.
For All Results
Consider the complete picture. AMH is one piece of fertility assessment. Combine with FSH, estradiol, ultrasound for antral follicle count, and assessment of other fertility factors.
Discuss with specialists. Reproductive endocrinologists can provide personalized interpretation and recommendations based on your specific situation and goals.
Related Health Conditions
Diminished Ovarian Reserve
Diminished ovarian reserve (DOR) means fewer eggs remain than expected for age. Low AMH is a primary diagnostic criterion. DOR affects fertility treatment success and may indicate less time for natural conception. It’s not the same as infertility — many women with DOR conceive — but it affects planning and treatment approaches.
Premature Ovarian Insufficiency
Premature ovarian insufficiency (POI), previously called premature ovarian failure, occurs when ovaries stop functioning before age 40. Very low or undetectable AMH with elevated FSH confirms the diagnosis. POI causes infertility, menopausal symptoms, and long-term health risks from estrogen deficiency. Egg donation is often needed for pregnancy.
Polycystic Ovary Syndrome (PCOS)
Women with PCOS typically have elevated AMH because they have many small follicles that produce AMH. High AMH supports PCOS diagnosis when combined with irregular periods and/or elevated androgens. Despite having many follicles, PCOS often causes anovulation, making conception difficult without treatment.
Infertility
AMH is a standard part of infertility evaluation, helping assess ovarian reserve as one factor in fertility. Low AMH may contribute to difficulty conceiving and affects treatment recommendations. However, AMH alone doesn’t diagnose or rule out infertility — many factors affect fertility.
Endometriosis
Endometriosis, especially ovarian endometriomas, is associated with reduced AMH and diminished ovarian reserve. Surgery for endometriomas further reduces ovarian tissue. Women with endometriosis may benefit from AMH testing to assess reserve, particularly before surgery or when planning pregnancy timing.
Ovarian Hyperstimulation Syndrome
Women with high AMH are at increased risk for ovarian hyperstimulation syndrome (OHSS) during fertility treatment. The many follicles respond vigorously to stimulation medications, potentially causing fluid shifts and other complications. AMH helps identify women who need modified protocols to prevent OHSS.
Related Biomarkers Often Tested Together
FSH — Another ovarian reserve marker; elevated FSH with low AMH confirms diminished reserve.
Estradiol — Tested with FSH on day 2-4 for complete ovarian reserve assessment.
LH — Part of complete hormonal evaluation; LH:FSH ratio elevated in PCOS.
Testosterone — Evaluated if PCOS suspected (high AMH with high androgens).
Antral Follicle Count (AFC) — Ultrasound measurement that correlates with AMH; together they assess ovarian reserve.
Note: Information provided in this article is for educational purposes and doesn’t replace personalized medical advice.
Frequently Asked Questions
Anti-Müllerian Hormone is produced by cells in small developing ovarian follicles. AMH levels reflect ovarian reserve — an estimate of how many eggs remain. Higher AMH generally means more eggs; lower AMH suggests fewer eggs remaining.
AMH can be tested any day of the menstrual cycle — it doesn’t fluctuate significantly like FSH and estradiol. This makes scheduling convenient.
No. Low AMH indicates fewer eggs but doesn’t mean infertility. Women with low AMH conceive naturally if they’re still ovulating. However, low AMH may mean less time remaining and can affect IVF success.
Not necessarily. High AMH indicates more eggs but is also associated with PCOS, which often causes ovulation problems. Quality matters as much as quantity, and age affects egg quality regardless of AMH.
It’s optional but can provide useful information for planning. Women who may delay childbearing, have family history of early menopause, or simply want information for future decisions may benefit from knowing their AMH.
AMH can help predict relative timing of menopause — very low AMH suggests menopause is approaching sooner than average. However, it can’t predict the exact timing with precision.
Most studies show hormonal contraceptives don’t significantly affect AMH, though some research suggests minor suppression. If in doubt, testing off contraception after a few months provides the most accurate picture.
No proven interventions reliably increase AMH or ovarian reserve. The egg pool is determined before birth and declines with age. Lifestyle factors like not smoking may help preserve reserve, but nothing significantly increases it.
References
Key Sources:
- Practice Committee of the American Society for Reproductive Medicine. Testing and interpreting measures of ovarian reserve: a committee opinion. Fertil Steril. 2020;114(6):1151-1157.
- Dewailly D, et al. The physiology and clinical utility of anti-Müllerian hormone in women. Hum Reprod Update. 2014;20(3):370-385.
- Nelson SM. Biomarkers of ovarian response: current and future applications. Fertil Steril. 2013;99(4):963-969.
