AFC: Which route of counting antral follicles are more exact ?

 

Q.1 What should be the size of AFC ?? AFC is defined as the total number of follicles smaller than 10mm in diameter, detected by TVS in both the ovaries in early follicular phase. The number of antral follicles in the ovaries is proportionally related to the size of primordial follicle stock from which they were recruited.

What are its interpretations in day to day clinical practice? Ans : AFC can predict hyper-stimulation as well as poor response after gonadotrophin stimulation. Number of retrieved oocytes correlated only with the antral follicle count and ovarian volume.

Therefore, the antral follicle count (AFC) is believed to represent the quantitative aspect of ovarian aging.^\

Q.2:  What is the rate of decline of AFC? Ans: Antral follicle count (AFC) declined linearly at a rate of 3.8% per year.

Q.3: Which route of USG? TAS or TVS? Ans : Transvaginal route is used to scan for counting antral follicles, as it gives high resolution images and allows counting even smaller) < 2mm) follicles. Q.4 On which day of cycle AFC is to be counted? Ans: AFC is always calculated on the baseline scan, i.e. day 2-3 of the menstrual cycle, when the selection of the dominant follicle (> 9mm in diameter) has not been done and the both oestrogen and progesterone are at their lower most levels.

Q.4: Should we count AFC by 2D or 3D?? Ans. AFC can be calculated by 2D ultrasound by scrolling through the entire ovary in any one axis and counting the follicles by eyeballing. But 3D ultrasound has also been widely used for calculation of number of antral follicles. Though, many researchers have shown that FNPO(follicle number per ovary)  with 2D or 3D do yield identical results. AFC can be reliably and accurately calculated by 3D US.

Q.5. What about 3 D  USG & also with SonoAVC ? Well these are   used for the purpose of more accuracy and reproducibility. Automated 3D measures however  provide reliable information on follicle number and size and can be used to individually identify each follicle.

It has also been shown that intraobserver and interobserver reliability of automated antral follicle counts made using three-dimensional ultrasound and

SonoAVC a preferred method and appear to be more reflective of ovarian reserve and response.

Q.7. what is the advantage of Sono VAC? Sono VAC takes longer to perform, because of the need for post processing, and obtains values that are lower than those obtained by the 2D and 3D-MPV techniques.

However, the AFC obtained by SonoAVC- PP(post processing) is likely to be lower because this method measures and color codes each follicle preventing recounting. But more exact value of AFC was acquired when counted by 3D US. Number of follicles > 12mm on day of oocyte retrieval correlated significantly with AFC counted by 3D US rather than 2D US.