Anti-Müllerian Hormone (AMH) is a protein produced by the granulosa cells inside the small follicles of the ovaries. A simple blood test measures the concentration of this hormone, providing a useful snapshot of the remaining egg supply. AMH testing has become a standard tool in fertility evaluations, offering insight into a woman’s potential reproductive timeline. Understanding what a “good” AMH level means is a frequent starting point for individuals exploring their fertility options, but this number is only one piece of the puzzle used to inform family planning decisions.
Understanding AMH and Ovarian Reserve
Anti-Müllerian Hormone acts as a proxy measurement for a woman’s ovarian reserve, the total quantity of eggs remaining in the ovaries. The hormone is secreted by the pre-antral and small antral follicles, the earliest stages of developing follicles. Since these small follicles reflect the dormant egg pool, AMH levels track the size of that remaining reserve. Higher AMH levels indicate a larger number of these follicles, suggesting a more robust egg count.
AMH reflects the quantity of the egg supply, not the quality of the eggs themselves. Egg quality, which is linked to age, is the primary factor determining whether an egg can develop into a healthy pregnancy. A woman with high AMH but advanced age may still face challenges due to lower egg quality. Because AMH levels stay relatively stable throughout the menstrual cycle, the test can be performed at any time, unlike other hormone tests.
Defining Optimal AMH Levels for Conception
The AMH level considered “good” for conception is relative, depending on a woman’s age and reproductive goals. The hormone is typically measured in nanograms per milliliter (ng/mL) or picomoles per liter (pmol/L). An AMH level suggesting a healthy egg supply and typical fertility potential generally falls between 1.0 ng/mL and 4.0 ng/mL (7 pmol/L to 28.6 pmol/L). This range is associated with a good response to ovarian stimulation used in fertility treatments.
Levels below 1.0 ng/mL are classified as low or diminished ovarian reserve. While this suggests a reduced egg count and a shorter reproductive window, natural conception is still possible, especially for younger women. A very low result, less than 0.5 ng/mL, indicates a significantly diminished reserve and suggests a greater need for proactive fertility planning. Conversely, a high AMH level, above 4.0 ng/mL, suggests an abundant ovarian reserve but can also be a marker for Polycystic Ovary Syndrome (PCOS). In fertility treatments, a level above 3.5 ng/mL may require caution to prevent Ovarian Hyperstimulation Syndrome (OHSS).
Factors That Influence AMH Levels
The most significant factor influencing AMH levels is reproductive aging. AMH levels peak around the mid-twenties and begin a gradual decline as a woman progresses toward menopause. This decline reflects the finite egg supply being naturally depleted over time. The rate of decline varies considerably, making AMH a useful tool for assessing a woman’s biological ovarian age compared to her chronological age.
AMH levels are also affected by certain medical conditions and external factors. Women with Polycystic Ovary Syndrome (PCOS) frequently exhibit elevated AMH levels, sometimes four times higher than the typical range. This occurs because a large number of small follicles accumulate in the ovaries without maturing properly. Conditions like severe endometriosis or previous ovarian surgery can physically damage the ovaries, leading to lower AMH results. Furthermore, current use of hormonal birth control can artificially suppress AMH levels by up to 30%, though levels typically rebound once the medication is stopped.
Interpreting Low AMH Results and Next Steps
Receiving a low AMH result can be concerning, but it is important to understand the full context. A low AMH indicates a reduced number of follicles and eggs, but it does not predict the monthly probability of achieving a natural pregnancy. For women with regular menstrual cycles, a low AMH primarily signals a potentially shorter timeline for conception and a need for urgent planning.
The immediate next step after a low AMH result is a comprehensive consultation with a fertility specialist. The specialist will likely recommend additional testing, such as an Antral Follicle Count (AFC) via ultrasound, and Follicle-Stimulating Hormone (FSH) levels, to confirm the ovarian reserve assessment.
Low AMH suggests that fertility treatments might be necessary sooner. Options include starting with less invasive treatments like Intrauterine Insemination (IUI), or moving directly to In Vitro Fertilization (IVF). Women with low AMH often produce fewer eggs in response to IVF stimulation, which may necessitate higher drug doses or multiple retrieval cycles. In cases of very low AMH, a specialist may discuss using donor eggs to maximize the chances of a successful pregnancy. AMH is a guide for treatment planning, not a final verdict on fertility, and all next steps should be determined with a medical professional.