To the Editor:
I read with much interest the manuscript by Mesen et al published recently in Fertility and Sterility (1). The authors’ intention was to retrospectively investigate the prevalence of genuine and false empty follicle syndrome (EFS) in a one single private ART unit. Among a total of 18,294 oocyte retrievals performed in 12,359 women, between 2004 and 2009, 46 cycles failed to recover an oocyte. Thirty five of these cycles had low ovarian response, defined as 14 mm diameter on the day of hCG administration, and were excluded from further evaluation. Of the remaining 11 cycles, two cases of genuine EFS and nine cases of false EFS were identified coming to the conclusion that genuine EFS is a extremely rare occurrence that deserves further investigation to understand ovarian biology and infertility.
Let me first acknowledge the efforts invested in this study evaluating a large cohort of ART cycles, performed in one single center, to gain insight into this enigmatic occurrence. Indeed, since the early days of IVF-ET treatment there has been an ongoing debate between investigators regarding EFS’s mere existence, incidence/prevalence, etiology and pathogenesis (2, 3). Despite its low incidence in the general infertile couples undergoing IVF-ET, EFS development has caused considerable concern to patients and doctors; mainly because of its significant implications when counseling these couples about their future reproductive performance. Furthermore, although the term is considered to be contradictio in terminis, it is still in use in current medical literature.
In their study Mesen et al apparently divided the 46 EFS cycles to genuine and false in accordance with a classification suggested earlier (4,5). While genuine EFS was defined as failure to retrieve oocytes from mature ovarian follicles following ovarian stimulation for IVF after apparently normal follicular development and steroidogenesis in the presence of optimal β-hCG levels on the day of oocyte retrieval, false EFS included all cases in which this definition did not apply (5). Read the rest of this entry »