Infertility
Diminished ovarian reserve
The role of AMH in reproduction
The ovarian reserve is the number of eggs still present in the ovaries. In its 2020 committee opinion, the American Society for Reproductive Medicine (ASRM) stresses an important difference: the ovarian reserve describes the quantity of eggs, not their quality. Quality determines whether the fertilized egg can lead to a pregnancy and a birth. The reserve falls with age, but women of the same age differ greatly.
AMH is one of the best-known tests in reproductive medicine, but its role is often not interpreted correctly. Many women experience a low AMH as a verdict on their fertility. The guidelines see it differently.
How does a woman lose her eggs?
Every woman is born with a set number of eggs. Before birth there are about six to seven million, at birth about one to two million, and at the first period about 300,000 to 400,000. No new eggs are formed. Every month a group of follicles starts to grow, but usually only one reaches ovulation. All the others are lost. Only about 400 to 500 eggs reach ovulation over a whole lifetime.
The loss is not steady. From about the age of 30 it speeds up, and after 37 it speeds up markedly. At the same time, egg quality falls. With age, the share of eggs with chromosomal abnormalities rises. This explains the lower chance of pregnancy and the higher risk of miscarriage. Menopause occurs when only about 1,000 follicles are left, on average at about 51.
How many eggs does a woman have over her life?
Eggs in the ovaries
Why does the reserve fall earlier?
Age. It is the most common cause. A low reserve in the late thirties or early forties is usually part of normal aging and not a disease. More in the article “Pregnancy at an older age”.
Surgery on the ovaries. Removing cysts, especially endometriomas, always removes healthy tissue with eggs as well. Repeated surgery and surgery on both ovaries reduce the reserve particularly sharply.
Endometriosis. Endometriomas harm the ovaries even without surgery. The iron in the cyst fluid causes oxidative stress and scarring and speeds up the loss of follicles. More in the article “Endometriosis and infertility”.
Chemotherapy and radiotherapy. Many cancer treatments damage the eggs. The extent depends on the type and dose of treatment and on the woman's age. Before such treatment, a discussion about preserving fertility is important. More in the article “Iatrogenic menopause”.
Genetic factors. The premutation of the FMR1 gene (fragile X syndrome), changes in the X chromosome as in Turner syndrome, and other rare genetic changes lead to an early loss of the reserve. An early menopause in the mother or sisters is an important clue.
Autoimmune diseases. The immune system can turn against the ovaries, for example together with an autoimmune disease of the adrenal glands or the thyroid.
Smoking. The toxins in tobacco speed up the loss of follicles. Women who smoke reach menopause on average one to two years earlier.
In many women with a diminished reserve, however, no specific cause is found.
Which tests measure ovarian reserve?
AMH. Anti-Müllerian hormone is produced by the small growing follicles. It is largely stable within the cycle and between cycles, and so it can be measured on any day. According to ASRM, AMH is more sensitive than FSH, because it falls before FSH rises. This is why it is the preferred test. The pill and other hormonal contraceptives can lower AMH, and this effect reverses after stopping. The laboratory method also affects the value.
Follicle count on ultrasound. Counting the small follicles of about 2 to 10 millimeters at the start of the cycle is, according to ASRM, equivalent to AMH when done by an experienced examiner.
FSH and estradiol. The FSH test takes place on days 2 to 4 of the cycle. A raised value points to a diminished reserve, but a normal value does not rule it out. FSH varies between cycles. A raised estradiol at the start of the cycle can mask a raised FSH. This is why the doctor reads it together with FSH.
What is no longer recommended? ASRM no longer recommends the clomiphene challenge test, because it adds no information. Ovarian volume is also of little value. Combining several values in complex models does not reliably improve prediction. AMH and ultrasound can disagree in up to 30% of women.
What does AMH show, and what does it not show?
AMH and the follicle count are good predictors of how many eggs can be collected during IVF and whether the ovaries respond weakly or too strongly to stimulation. For the chance of a pregnancy and a live birth, however, their predictive value is weak at best, according to ASRM.
For natural fertility this is even clearer. In the large “Time to Conceive” study (JAMA 2017) of 750 women aged 30 to 44, a low AMH or a high FSH did not lower the chance of pregnancy after six or twelve cycles. In another study of 1,202 women, a low AMH did not lower the number of pregnancies either. In women with infertility, too, reserve values did not improve the prediction beyond age. Age is the stronger factor.
Egg quality depends mainly on age. A 33-year-old woman with a low AMH has fewer eggs, but these eggs have the quality of her age. This is why the doctor always reads the value together with age, cycle, FSH, ultrasound and history.
From this, ASRM draws clear conclusions: a diminished reserve does not necessarily mean infertility. The values alone do not decide access to fertility treatment. Nor are they suitable as a “fertility test” for women without fertility problems, nor as a reason for egg freezing. That decision depends on age and life plans.
How does it differ from premature ovarian insufficiency?
A diminished reserve is not the same as premature ovarian insufficiency. According to the revised ESHRE guideline (2024), premature ovarian insufficiency is present in women under 40 with rare or absent periods for at least four months and a raised FSH (above 25). AMH can help when the picture is unclear. According to newer data, it affects about 3-4% of women. In this case, the woman needs tests to find the cause, including genetic testing and screening for autoimmune diseases. She also needs hormone replacement therapy to protect her bones, heart and brain, at least until the age of natural menopause. Rarely, ovarian function returns and a pregnancy is possible. More in the article “Premature ovarian insufficiency”.
What does it mean for treatment?
The most important message of a low AMH is that the reproductive phase of life is shorter and that time is important. A woman with a low AMH who wishes to become pregnant needs an assessment without delay and a plan with clear time limits.
In IVF, women with a poor response are called “low responders”. According to the ESHRE Bologna criteria, two of three features are needed: age 40 or over or another risk factor, a previous poor response and an abnormal reserve value. The POSEIDON criteria divide women into four groups by age and reserve: under or over 35, with a normal or diminished reserve. This classification is important, because the outlook for a young woman with few eggs is much better than for a woman over 40.
Even a very low AMH does not mean that treatment is pointless. In a large analysis of more than 5,000 treatments in women with extremely low AMH, the live birth rate was 9.5% per started cycle and 20.5% per embryo transfer. According to ASRM, such values are important for counseling, but not a reason to refuse treatment.
ESHRE does not recommend the many “supportive” treatments that are often offered to women with a poor response, such as androgens or growth hormone, because they have not been shown to increase live births. Treatment with platelet-rich plasma injected into the ovaries is not supported by evidence either. What matters is the right strategy: a timely decision, the right protocol, possibly collecting embryos from several cycles, and an honest discussion about the chances. With a very low reserve, especially after the age of 42, egg donation is an option with clearly higher success rates.
For women who are not yet thinking about pregnancy, a low AMH is a reason to discuss egg freezing. Results are best before the age of 35.
What about mental strain and quality of life?
A low AMH value often causes strong anxiety, especially when a woman learns about it without an explanation. Many women take it to mean “I will not be able to have a child”, although AMH does not predict natural fertility. Time pressure, comparisons with others and decisions about egg freezing or IVF add to the strain of daily life. ESHRE recommends making psychosocial support a routine part of care. A correct interpretation of the value, together with age and medical history, replaces panic with a plan.
The practice's approach
A low AMH on its own is neither a diagnosis nor a prognosis. The doctor reads it together with age, other hormones and the history. The goal of the practice is a clear explanation without panic and a plan that takes the remaining time into account, with timely referral when fertility treatment is the right path.
Sources: American Society for Reproductive Medicine Practice Committee – Testing and interpreting measures of ovarian reserve: a committee opinion, Fertility and Sterility 2020. ESHRE – Guideline Premature Ovarian Insufficiency (2024). ESHRE – Guideline Ovarian Stimulation for IVF/ICSI (2019). ESHRE – Good practice recommendations on add-ons in reproductive medicine (2023). Steiner AZ et al., JAMA 2017 (AMH and natural fertility). Ferraretti AP et al., ESHRE consensus on the definition of poor response (Bologna criteria), Human Reproduction 2011. Alviggi C et al., POSEIDON Group, Fertility and Sterility 2016. Gameiro S et al., ESHRE guideline: routine psychosocial care in infertility and medically assisted reproduction, Human Reproduction 2015. Gameiro S et al., Why do patients discontinue fertility treatment? A systematic review of reasons and predictors of discontinuation, Human Reproduction Update 2012. Baker TG, Proceedings of the Royal Society B 1963 (number of eggs). Faddy MJ et al., Human Reproduction 1992 (faster loss of follicles).