The Predictive Value of Antral Follicle Count (AFC) At Down Regulation Prior to IVF Stimulation is Better Than A Diagnostic AFC

Abstract

Antral follicles represent the cohort of oocytes surrounded by granulosa cells that may potentially develop into a lead follicle during an ovulatory cycle. During an IVF cycle, this cohort of follicles is stimulated using gonadotropins. AFC is used as a clinical marker for ovarian reserve and predictor of IVF cycle response. The present study aimed to determine if AFC at IVF down regulation is more predictive of stimulation outcomes than a diagnostic AFC. Eighty-three patients undergoing IVF from 2010 to 2011 were prospectively studied. All had a diagnostic AFC, FSH and estradiol as part of their evaluation. The patients' IVF protocol was selected from their diagnostic evaluation. At IVF, all patients underwent an ultrasound at down regulation and an AFC (pre-IVF AFC) was determined prior to stimulation. Analysis of correlation coefficients (R) was calculated using Spearman's rho. Average patient-age was 33.2 ± 5.2 years. Mean diagnostic AFC and pre-IVF AFC were 24.9 ± 14 and 23.2 ± 15 respectively. Mean follicles aspirated and oocytes retrieved were 25 ± 15 and 16.4 ± 9.6 respectively. Pre-IVF AFC was more predictive that diagnostic IVF for both follicles aspirated (R=0.74 vs 0.68, p<.05) and oocytes retrieved (R=0.58 vs 0.51, p<0.05). In cases where there was greater than 15% discordance between AFC values, pre-IVF AFC had a stronger correlation of stimulation outcomes compared to diagnostic AFC (Table).Tabled 1Correlation Coefficient when Discordance >15%Diagnostic AFCPre-IVF AFCFollicles Aspirated0.5610.621Oocytes Retrieved0.3410.4811p<0.05, N=45. Open table in a new tab 1p<0.05, N=45. Pre-IVF AFC is a better predictor of IVF stimulation, than a routine diagnostic AFC. This is likely because the pre-IVF AFC represents the follicles that will be stimulated during the index cycle. If a patient has discordant AFC values particular attention should be paid to the pre-IVF AFC, as this value will more likely to correlate with IVF outcomes and clinical decisions may need to be modified accordingly.