Ovulation by repeated human chorionic gonadotrophin in 'empty follicle syndrome' yields a twin clinical pregnancy

Compound heterozygous ZP1 mutations cause empty follicle syndrome in infertile sisters

Empty follicle syndrome (EFS) is a condition in which no oocyte is retrieved from mature follicles after proper ovarian stimulation in an in vitro fertilization procedure. Genetic evidence accumulates for the etiology of recurrent EFS without pharmacological or iatrogenic problems. In this study, we present two infertile sisters in a family with EFS after three cycles of standard ovarian stimulation with human chorionic gonadotrophin and/or gonadotropin-releasing hormone agonist therapy. Via whole-exome sequencing and cosegregation test, we identified compound heterozygous mutations in the gene of ZP1 in both of the infertile sisters. Coimmunoprecipitation tests and homology modeling analysis confirmed that both mutated ZP1 disrupt the formation of oocyte zona pellucida by interrupting the interaction among ZP1, ZP2, and ZP3. We thus propose that the specific mutations in ZP1 gene render a causality for the intractable EFS.

Empty follicle syndrome revisited: definition, incidence, aetiology, early diagnosis and treatment

In this review, the definition, incidence and possible causes of empty follicle syndrome (EFS), including molecular mechanisms that may underlie the syndrome, are discussed, along with prevention and treatment options. EFS is the complete failure to retrieve oocytes after ovarian stimulation, despite apparently normal follicle development and adequate follicular steroidogenesis. Two variants of EFS have been described: the 'genuine' form (gEFS), which occurs in the presence of adequate circulating HCG levels at the time of oocyte aspiration, and the 'false' form (f-EFS), which is associated with circulating HCG below a critical threshold. Heterogeneous HCG concentration thresholds, however, have been used to define gEFS, and to date no standardization exist. The situation is unclear when GnRH-analogues are used for ovulation trigger, as the threshold circulating LH and progesterone levels used to define EFS as 'genuine' are not established. The cause of fEFS has been clearly identified as an error in HCG administration at the time of ovulation trigger; in contrast, the cause of gEFS is still unclear, although some pathogenetic hypotheses have been proposed. Optimal treatment and prognosis of these patients are still poorly understood. Large, systematic multi-centre studies are needed to increase the understanding of EFS.

Predictive factors for oocyte retrieval failure in controlled ovarian hyperstimulation protocols: a retrospective observational cohort study

BACKGROUND

Oocyte retrieval failure following an ovarian hyperstimulation protocol is uncommon in assisted reproductive technology (ART) programs. We analyzed the predictive factors for oocyte retrieval failure following controlled ovarian hyperstimulation (COH) with gonadotropin-releasing hormone (GnRH) agonist and GnRH antagonist protocols in ART programs.

METHODS

This study was a retrospective cohort observational study. In total, 744 cycles from 361 patients who underwent controlled ovarian hyperstimulation with GnRH agonist long protocol or antagonist protocol were analyzed. Treatment cycles with oocyte retrieval failure and with one or more oocytes retrieved were compared to determine predictive factors for oocyte retrieval failure using univariate and multilevel multivariate logistic regression analyses.

RESULTS

Oocyte retrieval failure occurred in 38 cycles (5.1%). The oocyte retrieval failure rate of the GnRH antagonist protocol (8.1%) was significantly higher than that of the GnRH agonist long protocol (3.7%). On multilevel multivariate logistic analysis, cycles with GnRH antagonist protocol (odds ratio [OR] 3.06, 95% confidence interval [CI] 1.05-8.96), estradiol level on the day of human chorionic gonadotropin (hCG) injection (OR 0.997, 95% CI 0.996-0.998), and luteinizing hormone (LH) level on the day of hCG injection (OR 1.19, 95% CI 1.06-1.33) were independent predictive factors for oocyte retrieval failure. The efficacy of estradiol and LH levels on the day of hCG injection for predicting oocyte retrieval failure was evaluated using receiver operating characteristic curves. In all cycles, the areas under the curve (AUCs) for estradiol and LH were 0.84 and 0.63, respectively, for all cycles; 0.84 and 0.52, respectively, for cycles with GnRH agonist long protocol; and 0.81 and 0.82, respectively, for cycles with GnRH antagonist protocol.

CONCLUSIONS

Our results suggest that in cycles with GnRH antagonist protocol, the levels of estradiol and LH on the day of hCG injection might be predictive factors for oocyte retrieval failure. This relationship may provide useful information to both patients and physicians for developing better COH protocols in ART programs.

Empty follicle syndrome

Empty follicle syndrome (EFS) is a condition in which no oocytes are retrieved after an apparently adequate ovarian response to stimulation and meticulous follicular aspiration. EFS can be classified into 'genuine' and 'false' types according to hCG levels. It is a rare condition of obscure etiology. The existence of genuine EFS has been questioned and is still controversial. The limitation around EFS is that the definition of EFS is obscure. Management of patients with EFS is a challenge to physicians. No single treatment is known to be universally effective. However, patients should be adequately informed regarding the importance of correct hCG administration because improper hCG administration is a common and preventable cause of EFS. EFS is a syndrome that deserves additional study because such investigation could lead to a further understanding of ovarian biology and infertility.

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.

Empty follicle syndrome after GnRHa triggering versus hCG triggering in COS

PURPOSE

This study aimed to explore the incidence of empty follicle syndrome (EFS) in oocyte donors who had final oocyte maturation triggered with GnRHa and to compare the incidence of EFS in this group of patients with IVF patients who had final oocyte maturation with hCG.

METHODS

Data including 2034 oocyte donation cycles and 1433 IVF cycles performed between years 2009 and 2010 was retrospectively analyzed to identify cases of EFS in each group.

RESULTS

The incidence of EFS in the two groups did not differ significantly, 3.5% versus 3.1%, (n.s.).

CONCLUSIONS

This large retrospective analysis indicates that the incidence of EFS is not increased after GnRHa triggering as compared to hCG triggering.

Empty follicle syndrome-Still an enigma

Empty follicle syndrome (EFS), although rare with an incidence of 0.2-7%, is a frustrating condition where no oocytes are retrieved in in vitro fertilization (IVF), even though ultrasound and estradiol measurements show the presence of many potential follicles. It is a complex phenomenon that cannot be explained by low bioavailability of human chorionic gonadotrophin alone; neither can it be reliably diagnosed by the measurement of serum beta-human chorionic gonadotrophin (bhCG) on the day of oocyte retrieval (OR), except possibly when the bhCG concentration is very low. Here we report a case who underwent intracytoplasmic sperm injection (ICSI) for her partner's severe oligoasthenozoospermia. Controlled ovarian hyperstimulation (COH) was done in her first cycle of ICSI, using a gonadotrophin-releasing hormone (GnRH) agonist long protocol with follicle-stimulating hormone (FSH) and human menopausal gonadotrophin (HMG). However, as we were unable to retrieve any oocytes, her COH protocol was changed in the subsequent cycle with a successful outcome.

Empty follicle syndrome: the reality of a controversial syndrome, a systematic review

OBJECTIVES

To examine all case reports and studies of empty follicle syndrome (EFS) that have been published since the condition was first reported, in an attempt to identify trends or common features that may expose possible risk or causative factors.

DESIGN

Systematic review of all available literature obtained from PubMed, Ovid, and Embase.

SETTING

Academic unit.

PATIENT(S)

Review of all published case reports and case studies.

INTERVENTION(S)

All original work was assessed and labeled as "genuine" or "false" EFS according to set definitions.

MAIN OUTCOME MEASURE(S)

Genuine and false EFS. We defined genuine EFS as a failure to retrieve oocytes from mature ovarian follicles after ovarian stimulation for IVF after apparently normal follicular development and steroidogenesis in the presence of optimal beta-hCG levels on the day of oocyte retrieval. False EFS included all cases in which this definition cannot apply and often in which human error or a pharmaceutical inaccuracy has occurred.

RESULT(S)

By classifying all cases of EFS as "genuine" or "false" according to stated definitions, it was evident that a much greater proportion of cases of reported EFS, 67%, occurred as a result of human error and that "genuine empty follicle syndrome" is an even rarer event than previously presumed.

CONCLUSION(S)

Our report highlights the value of classifying cases of EFS as "genuine" or "false" and shows that more epidemiological data are required of "genuine" EFS cases to develop a clearer picture of the possible etiology.

Oocytes in the empty follicle: a controversial syndrome

OBJECTIVE

To assess the prevalence and etiology of the empty follicle syndrome (EFS).

DESIGN

Observational longitudinal study.

SETTING

Tertiary fertility centers.

PATIENT(S)

All patients beginning in vitro fertilization (IVF) treatment from December 2002 to November 2004 were included. Couples undergoing IVF with donor oocytes or participating in an experimental IVF study were excluded from analysis.

INTERVENTION(S)

Identification of EFS cycles. Comparing ovarian hyperstimulation strategy, follicle count, and timing of human chorionic gonadotropin (hCG) for final oocyte maturation of the EFS cycles with normal IVF cycles.

MAIN OUTCOME MEASURE(S)

Number of follicles punctured, number of oocytes recovered, previous and future IVF attempts, and serum hormone levels.

RESULT(S)

Twenty-five of a total of 1,849 patients were identified with an EFS cycle. Reasons for occurrence of EFS cycles were mistiming of hCG for final oocyte maturation, premature ovulation, and poor ovarian response. None of the affected patients had experienced EFS cycles in earlier IVF attempts nor were there any recurrence in subsequent treatments.

CONCLUSION(S)

Accurate timing of induction of final oocyte maturation, properly scheduled ovarian hyperstimulation, instruction of patients and doctors, and full workup for IVF are essential for the successful recovery of oocytes. Occurrence of EFS in IVF can normally be attributed to a failure of at least one of these factors and probably rarely or never occurs otherwise.

Pericentric inversion of chromosome 2 in a patient with the empty follicle syndrome: Case report

The empty follicle syndrome (EFS) is defined as a lack of retrieved oocytes from follicles, at the time of repeated aspiration and flushing, following ovulation induction. The actual mechanism responsible for the EFS is still unknown. The aim of this study was to offer more information regarding the possible connection of this syndrome with pericentric inversion of chromosome 2. We give a case report of a patient who had multiple failed IVF attempts, due to the absence of oocyte and granulosa cells in the follicular fluid, following oocyte retrieval in both stimulated and natural cycles. Chromosomal analysis showed the presence of a pericentric inversion of chromosome 2: 46,XX,inv(2)(p11q21) in the female partner karyotype, while the male partner had a normal karyotype. Our case showed possible genetic factor influence in the aetiology of EFS.

Controlled natural cycle IVF with antagonist use and blastocyst transfer

A method of controlled natural cycle IVF (CONCIVF) was sought to provide simpler and shorter treatment without the risks of ovarian hyperstimulation syndrome and multiple pregnancies. A total of 138 couples with normal ovulation and normal sperm parameters, in whom the women were <40 years old, were the candidates for this study. Gonadotrophin-releasing hormone antagonist was used before human chorionic gonadotrophin (HCG) administration if LH increased to a concentration of 10 mIU/ml before HCG injection. Treatment was initiated at > or =16 mm follicular growth and at oestradiol concentrations > or =400 pmol/l with 5000 IU HCG induction. All the embryos were cultured to the blastocyst stage and transferred only if they reached early or advanced blastulation. A total of 126 patients underwent oocyte retrieval. In 102 cases, one oocyte was retrieved; 95% of the oocytes fertilized, 99% cleaved and 47.9% achieved the blastocyst stage. The implantation rate per blastocyst transfer was 53.3% and the live-birth rate per embryo transfer was 40%. Therefore, CONCIVF with blastocyst transfer gives acceptable blastocyst development and implantation rates without the long- or short-term side effects of ovulation induction.

Recurrent empty follicle syndrome

We report a case of a recurrent empty follicle syndrome. The patient was admitted to our intracytoplasmic injection program because of her partner's azoospermia. Ovarian stimulation was accomplished using gonadotrophin therapy after treatment with oral contraceptive pills followed by gonadotrophin-releasing hormone agonist. Thirty-six hours after the administration of HCG (human chorionic gonadotrophins), transvaginal oocyte retrieval yielded no oocytes despite the aspiration and flushing of all available follicles. Two years later, a second treatment cycle was started using the same pituitary desensitisation and ovarian stimulation regimens. HCG from a different batch with respect to that used in the first treatment cycle was administered. Aspiration and repeated flushing of all follicles of one ovary failed to yield any identifiable oocyte. The beta-HCG and progesterone serum concentrations on the day of retrieval were 181 mIU/mL and 3.79 ng/mL, respectively. New oocyte retrieval was planned 6 h after the first attempt for aspiration of follicles. Again, no ova were obtained at this second trial despite the aspiration of the all follicles. As to our knowledge this is the first report of recurrent EFS (empty follicle syndrome) and managed without repeating the HCG injection on the day of unsuccessful oocyte retrieval.

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.

Recurrent empty follicle syndrome successfully treated with recombinant human chorionic gonadotrophin

We report a case of a patient with polycystic ovary syndrome and primary infertility who was admitted to our in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) programme because of her partner's severe oligozoospermia and asthenozoospermia. Ovarian stimulation was accomplished in the three treatment cycles using gonadotrophin therapy after a dual approach with ovarian suppression using oral contraceptive pills followed by gonadotrophin-releasing hormone agonist therapy. Oocyte retrieval was unsuccessful in the first two treated cycles despite the fact that human chorionic gonadotrophin (HCG) from three different batches was used. In the third treatment cycle, recombinant HCG was used and five oocytes were retrieved. This is the first report of recurrent empty follicle syndrome despite the use of different batches of commercially available urinary HCG, and of its successful treatment using recombinant HCG.

Severe ovarian hyperstimulation syndrome following salvage of empty follicle syndrome

We report a case of severe ovarian hyperstimulation syndrome (OHSS) following a rescue of empty follicle syndrome (EFS). This suggests that the risk of developing OHSS remains unaltered even in the presence of EFS. The case supports the possibility of obtaining oocytes that fertilize and cleave normally after a second dose of human chorionic gonadotrophin (HCG) and a repeat oocyte retrieval. It supports the suggestion that the follicles are not necessarily empty in EFS. It demonstrates further that OHSS cannot be prevented by aspiration of follicular fluid and patients with large numbers of follicles and EFS must be warned of this potential complication.