Reproductive Health Glossary

A hormone produced by cells in ovarian follicles. AMH levels reflect the number of follicles in the ovaries and are commonly used as a marker of ovarian reserve. AMH levels naturally decline with age.

The number of small follicles (2-10mm) visible on an ultrasound during the early part of your menstrual cycle. AFC provides information about ovarian reserve and is often measured during fertility assessments.

Menopause that occurs between ages 40 and 45. This is earlier than average but distinct from premature ovarian insufficiency, which occurs before age 40. Early menopause may happen naturally or result from medical treatments such as surgery.

A group of hormones that play a key role in the menstrual cycle and reproductive system. Estrogen levels fluctuate during perimenopause and decline after menopause, which can affect bone density, heart health, and other body systems.

A small fluid-filled sac in the ovary that contains a developing egg. Each menstrual cycle, follicles grow and typically one releases a mature egg. The total number of follicles in the ovaries decreases naturally over time.

A hormone produced by the pituitary gland (located at the base of the brain) that signals the ovaries to develop follicles. FSH levels tend to rise as ovarian reserve decreases, which is why higher FSH levels are often seen as people approach menopause.

A sudden feeling of warmth, usually most intense over the face, neck, and chest. Hot flashes are one of the most common symptoms of perimenopause and menopause. They can last from a few seconds to several minutes and may be accompanied by sweating, flushing, or chills.

A treatment that uses medications containing hormones (such as estrogen, sometimes with progesterone) to help manage symptoms of menopause. Also called hormone replacement therapy (HRT). Whether MHT is appropriate depends on individual health factors, and decisions should be made with a healthcare provider.

Another term for perimenopause—the period of time leading up to menopause when hormone levels begin to change and menstrual cycles become irregular. You may see this term used in medical literature and by healthcare providers.

Defined as the point when someone has gone 12 consecutive months without a menstrual period (not due to other causes like pregnancy or illness). In the United States, the average age of menopause is 51, though it commonly occurs anywhere between ages 45 and 55.

A term describing the number of eggs remaining in the ovaries. Ovarian reserve declines naturally with age. It can be estimated through blood tests (like AMH) and ultrasound measurements (like AFC).

The transition period leading up to menopause. During this time, hormone levels fluctuate, which can cause irregular periods and symptoms such as hot flashes, sleep changes, and mood shifts. Perimenopause ends when menopause is reached.

The phase of life after menopause. Because estrogen levels are lower during this time, maintaining bone health and heart health becomes especially important. Many people find that some perimenopause symptoms ease during postmenopause, though experiences vary.

A condition where the ovaries stop functioning normally before age 40. This leads to irregular or absent periods and reduced fertility. POI is different from early menopause and has various possible causes, including genetic factors, autoimmune conditions, or medical treatments. A healthcare provider can help with diagnosis and management.