It is important to know the ovarian reserve or, more precisely, the number of eggs in their follicles (antral follicles) that are available for stimulation at the beginning of a cycle with the potential to ovulate in that cycle.
With the improvement in technology and 3D scanning technology, the number of antral follicles that are present at the beginning of the cycle can now be fairly accurately counted through vaginal ultrasound examination.
The sum of the follicles in the ovaries can indicate what will be the response to treatment involving stimulation of the ovaries, particularly for in-vitro fertilization (IVF) can give a rough guide to the chances of a successful treatment. This enables the planning of the treatment doses.
An antral follicle count of less than five usually indicates a low ovarian reserve, resulting in the need for relatively high doses of medication in order to produce a reasonable number of eggs for IVF.
An antral follicle count of greater than 15, seen in such conditions as polycystic ovary syndrome, indicates a very good chance of harvesting a good number of eggs. This usually demands only a moderate dose of stimulating medication.