What is Antral Follicle Count

When a baby girl is born, she has all the eggs she will ever have produced for the rest of her life. At the onset of puberty, the young woman starts losing those eggs with every menstrual cycle until menopause. With each passing cycle, fewer eggs are left in her ovarian reserve, or remaining egg supply.

Available in assistive reproductive therapy centers in the Philippines, antral follicle count is an ultrasound examination for ovarian reserve, and allows your physician to not only visualize the quantity, but also the quality of the follicles, and thus accurately evaluate a woman’s ovarian reserve. This is a key factor in determining whether she has a fertility issue that needs to be addressed.

Antral follicles are small cavities ranging in diameter from 2-8 mm. These resting follicles are visualized using vaginal ultrasound and easily measured and counted. Using antral follicle count as well as the age of the female patient, doctors can estimate ovarian reserve, determine the expected response to ovarian stimulating medications, and even the chance for IVF success for resulting in a pregnancy.

The number of visible antral follicles on ultrasound allows the ultrasonographer and physician to estimate the number of small, dormant primordial follicles within the ovary that have yet to develop. Within every primordial follicle is an immature oocyte that has the potential to develop into a mature oocyte to be released during ovulation. When more antral follicles are visible, more primordial follicles are available in the future. Also, since the follicles are the eventual target of ovarian stimulating medications, more follicles would be stimulated, thus leading to a higher success rate for in-vitro fertilization.

Conversely, in cases where the antral follicle count is low, success rates are lower, and an IVF cycle may be subject to cancellation.

What is considered a good number of follicles?

The following table illustrates some general guidelines for assessing antral follicle count:

Number of antral follicles Expected outcome of ovarian stimulating drugs Candidacy for IVF success
Less than 4 Very small or no response to stimulation Should not consider attempting IVF at all
4-6 Possibly poor response, high dose of FSH may be required Higher than average rate of IVF cancellation; low pregnancy rates
7-10 Low response to stimulation, high dose of FSH may be required Higher than average rates of IVF cancellation; moderately reduced chances for pregnancy
11-15 Response to stimulation may be low or adequate Pregnancy rates slightly reduced
16-30 Normal antral count, likely to respond well to low doses of FSH, slight risk of ovarian overstimulation. Very low risk for IVF cycle cancellation. Very good overall success rates for pregnancy
More than 30 Beware of high response to low doses of FSH. High risk for overstimulation and ovarian hyperstimulation syndrome Very good pregnancy rate