Empty follicle syndrome in perimenopausal patients

Is the time interval between HCG administration and oocyte retrieval associated with oocyte retrieval rate?

The aim of this study was to evaluate whether prolongation of the time interval between HCG administration and oocyte retrieval, from 36 h to 38 h, affects oocyte retrieval rate in women undergoing ovarian stimulation with gonadotrophins and GnRH antagonists for IVF. One hundred and fifty-six normo-ovulatory women were randomized to have oocyte retrieval performed 36 h (n = 78) or 38 h (n = 78) following HCG administration. Oocyte retrieval rate was defined as number of cumulus-oocyte-complex (COC) retrieved/follicle ≥ 11 mm present on day of HCG administration. No significant differences were observed between the groups regarding baseline characteristics. Moreover, no significant difference was observed between the groups regarding oocyte retrieval rate (difference: + 1.2%, 95% CI for difference between medians: -4.5 to +12.1). The median (95% CI for the median) was not significantly different between the groups regarding number of cumulus-oocyte-complexes (COCs) retrieved: 5.5 (5.0-7.0) versus 6.0 (5.0-6.2), respectively, and fertilization rates: 57.7% (50.0-66.7) versus 50.0% (44.8-65.5), respectively. Live birth rates were similar between the groups (20.5% versus 16.7%, RD: + 3.8%, 95% CI: -8.5 to +16.1, respectively). Prolongation of time interval between HCG administration and oocyte retrieval from 36 h to 38 h does not affect oocyte retrieval rate.

Empty follicle syndrome: successful treatment in a recurrent case and review of the literature

Empty follicle syndrome is a condition in which no oocytes are retrieved after an apparently adequate ovarian response to stimulation and meticulous follicular aspiration. It is a rare condition of obscure etiology. A patient with primary infertility who underwent seven assisted reproductive technique cycles is described. In spite of a satisfactory ovarian response, aspiration yielded no oocytes in four cycles and 1-4 low quality oocytes in three cycles. In the index treatment cycle, ovulation was triggered using GnRH agonist 40 h prior to ovum pickup and hCG was added 6 h after the first trigger. Eighteen oocytes were recovered, of which 16 were mature and were inseminated by ICSI. Two embryos were transferred 48 h after aspiration and nine embryos were cryopreserved. The patient conceived and delivered a healthy boy at 38 weeks of gestation. The literature is reviewed and possible etiologies and treatment options of this enigmatic syndrome are suggested.

Unsuccessful oocyte retrieval: technical artefact or genuine 'empty follicle syndrome'?

Unsuccessful oocyte retrieval after apparently successful ovarian stimulation (also referred to as 'empty follicle syndrome') occurs in 1-7% of women undergoing assisted reproductive techniques. A literature review was performed, as individual studies have reached differing conclusions on the aetiology and treatment or management of the phenomenon. The aetiology is not clear, but probably multifactorial, and occurs in natural and stimulated cycles. In many cases, technical problems such as errors in human chorionic gonadotrophin (HCG) administration or defects in HCG batches can be identified, but this is not sufficient to account for all reported cases. The term empty follicle syndrome is inappropriate in cases in which such procedural factors can be identified. In many patients, however, unsuccessful oocyte retrieval appears to be due to an underlying ovarian dysfunction, and some may have a genuine empty follicle syndrome. Appropriate measures, such as monitoring of serum beta-HCG, should be taken to minimize the risk of unsuccessful oocyte retrieval. This review discusses the potential causes of unsuccessful oocyte retrieval, its clinical implications, and potential solutions to this clinical problem.

The empty follicle syndrome

The empty follicle syndrome (EFS) is characterized by the lack of retrieved oocytes from follicles after ovulation induction and apparently normal follicular development for in vitro fertilization, despite repeated aspiration and flushing. The underlying mechanism of the EFS remains hypothetical. Some Authors have suggested that it is related to the "cause" leading to female infertility, whereas others have pointed to the alternative suggestion that it might reflect dysfunctional folliculogenesis, with early oocyte atresia and apparently normal hormonal response. Moreover, some Authors believe that the EFS does not exist, and that the oocyte retrieval failure is a pharmacological fault. The risk of recurrence is higher as the age of the patients increases. The EFS cannot be predicted by the pattern of ovarian response to stimulation either sonographically or hormonally. Consequently, the diagnosis of EFS is retrospective. Whatever the underlying cause of an EFS cycle, patients with an EFS cycle should be counselled regarding the possibility of recurrence of such an event in future cycles.