Anti-Müllerian Hormone (AMH) is an indicator of a woman’s ovarian reserve, the quantity of eggs remaining in the ovaries. Produced by ovarian follicles, AMH measurement helps assess a woman’s potential egg supply.
What is AMH and Why is it Measured?
AMH is a protein hormone secreted by granulosa cells in the small, growing follicles within the ovaries. These follicles are immature egg-containing sacs. AMH levels in the blood reflect the number of these developing follicles, providing an estimate of ovarian reserve.
Measuring AMH is important in reproductive medicine. It helps assess a woman’s fertility potential and the quantity of eggs available. This blood test also assists in diagnosing conditions like Polycystic Ovary Syndrome (PCOS) and guides fertility treatment planning, including medication dosages for in vitro fertilization (IVF) to stimulate egg production.
Understanding Your AMH Results
Interpreting AMH results involves understanding typical ranges and their relation to ovarian reserve, which refers to the number of eggs a woman has remaining. AMH levels are measured in nanograms per milliliter (ng/mL) and generally decline with age. A higher AMH level typically suggests a greater number of eggs, while a lower level indicates a shrinking egg supply.
While lab-specific ranges can vary, a “normal” AMH level is often considered to be between 1.0 ng/mL and 3.0 ng/mL, indicating a healthy egg supply. Levels below 1.0 ng/mL are commonly classified as low, suggesting diminished ovarian reserve (DOR). For instance, a severely low level might be around 0.4 ng/mL.
Very high AMH levels, often above 3.0 ng/mL or 4.0 ng/mL, can indicate a robust ovarian reserve and potentially a higher number of eggs. However, very high levels can also be a sign of Polycystic Ovary Syndrome (PCOS), a hormonal disorder characterized by an increased number of small follicles. Conversely, very low AMH levels, particularly those approaching zero, are associated with diminished ovarian reserve or nearing menopause, as egg supply depletes. It is important to remember that AMH levels are relative to age, and personalized interpretation by a healthcare provider is essential.
For example, typical AMH levels vary significantly by age: a 25-year-old might have an average of 3.0 ng/mL, while a 35-year-old might have 1.5 ng/mL, and a 45-year-old typically has 0.5 ng/mL. These age-specific declines are natural, reflecting the gradual reduction in egg supply over time.
Factors That Influence AMH Levels
Age is the primary determinant of AMH levels, with levels naturally decreasing as a woman gets older due to the continuous decline in her ovarian reserve. However, several other factors can also influence AMH measurements. For instance, certain medical conditions can impact AMH levels.
Endometriosis, a condition where tissue similar to the uterine lining grows outside the uterus, has been linked to lower AMH levels in some studies. Autoimmune diseases, where the body’s immune system mistakenly attacks its own tissues, may also be associated with lower AMH levels, including conditions like thyroid autoimmunity, type 1 diabetes, and rheumatoid arthritis.
Ovarian surgery, particularly procedures involving the removal of ovarian cysts like endometriomas, can lead to a significant decrease in AMH levels post-operation. This reduction can be more pronounced in cases of bilateral surgery or larger cysts. Genetic factors also play a role in an individual’s AMH levels and the rate at which they decline.
Lifestyle factors can also have some influence. For example, current smoking has been associated with lower AMH levels, suggesting a potential negative impact on ovarian reserve. While some studies suggest possible links between diet, stress, or extreme exercise and AMH, their direct and consistent impact is less established.
AMH and Fertility Planning: What to Do Next
AMH is a valuable tool for assessing ovarian reserve, but it is only one component of the broader fertility picture. It provides information about the quantity of eggs, but it does not indicate egg quality, which is primarily influenced by age. A woman with a low AMH level can still conceive naturally, as it only takes one healthy egg to achieve pregnancy.
Given these nuances, consulting a fertility specialist or healthcare provider is important for a comprehensive evaluation. This evaluation typically includes AMH testing alongside other fertility assessments, such as Follicle-Stimulating Hormone (FSH) and Antral Follicle Count (AFC). A thorough medical history and physical examination also contribute to a complete understanding of a woman’s reproductive health.
Based on a holistic assessment, a healthcare provider can discuss potential next steps tailored to individual circumstances. This might involve further diagnostic tests or a discussion about lifestyle adjustments. For some, the results may lead to discussions about fertility treatment options, such as IVF, and how AMH levels might influence protocols.