Recurrence of empty follicle syndrome with stimulated IVF cycles

To determine the incidence of recurrent empty follicle syndrome (EFS) and to analyse the factors associated with this phenomenon.

Retrospective analysis comparing all EFS cycles with cycles in which oocytes were retrieved in our in vitro fertilization (IVF) unit between 1998 and 2006.

Of 8292 IVF cycles, 163 (2.0%) resulted in empty follicles. Risk factors for EFS included advanced age (37.7 ± 6.0 years vs. 34.2 ± 6.0 years, p < 0.001), longer infertility (8.8 ± 10.6 years vs. 6.3 ± 8.4 years, p < 0.05), higher baseline follicle-stimulating hormone levels (8.7 ± 4.7 IU/L vs. 6.7 ± 2.9 IU/L, p < 0.001) and lower E2 levels before the human chorionic gonadotropin injection (499.9 ± 480.9 pg/mL vs. 1516.3 ± 887.5 pg/mL, p < 0.001) compared with cases in which ova were retrieved. Among patients with EFS, recurrent EFSs occurred in 15.8% of subsequent cycles.

The EFS is a sporadic event in the majority of patients. However, in about 16% of the patients, EFS may recur. These cases may be a variant form of poor response and patients with repetitive EFS syndrome should be counseled concerning their chances to conceive.