Antral Follicle Count (AFC) is an ultrasound measurement used to estimate the number of small follicles present in the ovaries at the beginning of the menstrual cycle. These follicles contain immature eggs and can be seen using a transvaginal ultrasound.

AFC is one of the tools fertility specialists use to assess ovarian reserve, or an estimate of the remaining egg supply. It can also help your fertility specialist understand how your ovaries may respond to medications used during fertility treatment, such as IVF.

An AFC is typically performed during the early follicular phase of the menstrual cycle, often between cycle days 2 and 5. The follicles in each ovary are counted, and the numbers are combined to determine the total antral follicle count.

It is important to remember that AFC provides information about egg quantity, not egg quality. A person's age and other factors are also important when evaluating fertility and reproductive potential. Your fertility specialist will interpret your AFC together with other information, such as AMH levels, medical history, menstrual cycle patterns, and other fertility testing.

Related terms: Ovarian Reserve, AMH, Fertility Testing, Transvaginal Ultrasound, IVF, Follicle