Girsh E*, Makovski Lev-Tov
Empty follicle syndrome (EFS), reported in patients undergoing IVF treatment with no oocytes is obtained after ovarian stimulation. The publications regarding EFS are limited and there is no consensus of its etiology. The aim of our study was to characterize the cycles with EFS and evaluate the possible reasons for its occurrence. The incidence of EFS in our cohort was 4.9% per cycle or 6.2% per patient. On the day of hCG administration the mean E2 and P4 levels were 1856 ± 1154 pg/ml and 0.98 ± 0.87 ng/ml, respectively, in our patients (control group) as compared to 610 ± 178 pg/ml (p<0.05) and 0.7 ± 0.4 ng/ml, respectively, for cycles with EFS. The mean follicle number per patient in the control group was 6.4 ± 4.1; however, the mean follicle number in patients with no oocytes in the follicular fluid (FF) was 2.5 ± 2.2. In the EFS group the measured level of AMH was 0.5 ± 0.3. Double dose of rec-hCG in consecutive cycles of the EFS group, using a similar COH protocol or changed COH regimen with regular dose of rec-hCG, resulted in oocyte aspiration in most cases with previous EFS cycles. From 150 oocytes retrieved in the 34 successful consecutive cycles of the EFS group, 37% of oocytes were immature (MI stage) and 63% mature (M II) oocytes, the same percentage as was found in our control sub-group (women over 35 years old). We suggest that EFS may be the result of a delayed maturation of oocyte-cumulus complexes. The cases of EFS are sporadic and, in our opinion, can’t be defined as a syndrome. We suggest the use of a different name for EFS, such as “Failure of Oocyte Retrieval” (FOR).