Oocytes in the empty follicle: a controversial syndrome

Whole exome sequencing identifies a novel homozygous missense mutation of LHCGR gene in primary infertile women with empty follicle syndrome

AIM

The genetic basis of empty follicle syndrome (EFS) is largely unknown, and the aim of this study was to investigate the genetic causes of EFS in primary infertile women.

METHODS

Four affected women diagnosed with anovulation were recruited, and whole exome sequencing (WES) was requested for the genetic diagnosis of the cases. One hundred healthy controls were verified by Sanger sequencing.

RESULTS

A novel homozygous variant of the LHCGR gene (NM_000233:c.1847C>A) was revealed in one affected individual by WES. Trios analysis of the mutation revealed an autosomal recessive pattern. This LHCGR variant was absent in 100 healthy controls and predicted to be highly damaging to the function of LHCGR.

CONCLUSIONS

The novel variant extends the mutational spectrum of the LHCGR gene associated with female sterility, which promotes the prognostic value of testing for LHCGR mutations in infertile women with EFS.

Risk factors for low oocyte retrieval in patients with polycystic ovarian syndrome undergoing in vitro fertilization

BACKGROUND

The number of oocytes retrieved does not always coincide with the number of follicles aspirated in in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment. Patients with high expectation of retrieval sometimes obtain few oocytes, which may be induced by improper operation or therapeutic factors. The purpose of this study was to evaluate the distribution data of oocyte retrieval rate (ORR) and to explore the risk factors for low ORR in patients with polycystic ovary syndrome (PCOS) undergoing IVF/ICSI.

METHODS

A total of 2478 patients with PCOS undergoing IVF/ICSI were involved in this retrospective case-control study from March 2016 to October 2021. The oocyte retrieval rate was calculated as the ratio of the number of obtained oocytes to the number of follicles (≥ 12 mm) on the trigger day. Patients were divided into a low ORR and a normal ORR group with the boundary of one standard deviation from the mean value of ORR. The patient characteristics, treatment protocols, serum hormone levels, and embryonic and pregnancy outcomes were analyzed.

RESULTS

The ORR exhibited a non-normal distribution, with a median of 0.818. The incidence of complete empty follicle syndrome was 0.12% (3/2478). The proportion of patients in the low ORR group who received the progestin-primed protocol was significantly higher than that in the normal ORR group (30.30% vs. 17.69%). A logistic regression analysis showed that the serum estradiol level/follicle (≥ 12 mm) ratio (OR: 0.600 (0.545-0.661)) and progesterone level (OR: 0.783 (0.720-0.853)) on the trigger day were significant factors in the development of a low ORR, with optimal cutoff values of 172.85 pg/ml and 0.83 ng/ml, respectively, as determined by receiver operating curve. Fewer high-quality embryos (2 vs. 5) and more cycles with no available embryos (5.42% vs. 0.43%) were found in the low ORR group.

CONCLUSIONS

For patients with PCOS, low estradiol levels/follicles (≥ 12 mm) and progesterone levels on the trigger day and the use of the progestin-primed protocol could be risk factors for low ORR, which leads to a limited number of embryos and more cycle cancellations.

Oocyte maturation abnormalities - A systematic review of the evidence and mechanisms in a rare but difficult to manage fertility pheneomina

A small proportion of infertile women experience repeated oocyte maturation abnormalities (OMAS). OMAS include degenerated and dysmorphic oocytes, empty follicle syndrome, oocyte maturation arrest (OMA), resistant ovary syndrome and maturation defects due to primary ovarian insufficiency. Genetic factors play an important role in OMAS but still need specifications. This review documents the spectrum of OMAS and to evaluate the multiple subtypes classified as OMAS. In this review, readers will be able to understand the oocyte maturation mechanism, gene expression and their regulation that lead to different subtypes of OMAs, and it will discuss the animal and human studies related to OMAS and lastly the treatment options for OMAs. Literature searches using PubMed, MEDLINE, Embase, National Institute for Health and Care Excellence were performed to identify articles written in English focusing on Oocyte Maturation Abnormalities by looking for the following relevant keywords. A search was made with the specified keywords and included books and documents, clinical trials, animal studies, human studies, meta-analysis, randomized controlled trials, reviews, systematic reviews and options written in english. The search detected 3,953 sources published from 1961 to 2021. After title and abstract screening for study type, duplicates and relevancy, 2,914 studies were excluded. The remaining 1,039 records were assessed for eligibility by full-text reading and 886 records were then excluded. Two hundred and twenty seven full-text articles and 0 book chapters from the database were selected for inclusion. Overall, 227 articles, one unpublished and one abstract paper were included in this final review. In this review study, OMAS were classified and extensively evaluatedand possible treatment options under the light of current information, present literature and ongoing studies. Either genetic studies or in vitro maturation studies that will be handled in the future will lead more informations to be reached and may make it possible to obtain pregnancies.

Genuine Empty Follicle Syndrome: Role of Double Trigger and Delayed Oocyte Retrieval (DTDO)

BACKGROUND

Empty follicle syndrome (EFS) is a condition of undetermined etiology where no oocytes are retrieved in an ART cycle despite adequate response to ovarian stimulation and diligent follicular aspiration. Because of the rarity of this condition, no much published strategies are available to tackle this.

AIM

The aim of this study was to evaluate whether sequential administration of gonadotropin-releasing hormone agonist (GnRHa) and human chorionic gonadotropin (hCG) as a trigger at 40 h and 36 h, respectively, before oocyte retrieval (OCR) could correct genuine empty follicle syndrome (GEFS).

STUDY SETTING AND DESIGN

This retrospective observational cohort study was conducted in a tertiary fertility center over a period of 6 years from January 2014 to December 2019. Patients with a history of GEFS were administered GnRHa and recombinant hCG subcutaneously at 40 h and 36 h, respectively, before OCR, i.e., double trigger and delayed oocyte retrieval (DTDO) (n = 13). The primary outcome measures studied were number of mature oocytes retrieved, oocyte maturation index (OMI), number of fertilized oocytes, and number of embryos available for embryo transfer. The secondary outcome measures were clinical pregnancy rate (CPR), miscarriage rate (MR) and live birth rate (LBR) per first frozen embryo transfer (FET) cycle, incidence of inadvertent premature ovulation, and ovarian hyperstimulation syndrome.

STATISTICAL ANALYSIS

Comparison between the groups was analysed by Fisher's exact test and paired t-test.

RESULTS

Patients in the DTDO group showed a significant improvement (P < 0.01) in the number of mature oocytes retrieved, OMI, number of fertilized oocytes, and number of embryos available for embryo transfer. In the first FET cycle, CPR (44.44%), LBR (44.44%), and MR (11.11%) were observed in the DTDO group.

CONCLUSION

Our findings implicate that double trigger and delayed OCR (DTDO) is a safe and efficacious treatment strategy for GEFS.

The critical role of ZP genes in female infertility characterized by empty follicle syndrome and oocyte degeneration

OBJECTIVE

To identify the major causative gene(s) of genuine empty follicle syndrome (GEFS) characterized by oocyte degeneration.

DESIGN

Genetic and functional studies.

SETTING

University-based reproductive medicine center.

PATIENT(S)

Thirty-five unrelated women with GEFS and oocyte degeneration.

INTERVENTION(S)

Whole-exome sequencing (WES) and targeted Sanger sequencing.

MAIN OUTCOME MEASURE(S)

Variants predicted by software and the functional effects of variants assessed via Western blot and immunofluorescence in Chinese hamster ovary (CHO) cells.

RESULT(S)

We identified zona pellucida (ZP) gene variants in 18 individuals, which included 20 variants in the ZP1 gene, two variants in the ZP2 gene, and one previously reported recurrent variant in the ZP3 gene. The women carrying ZP variants constituted 51.43% of the GEFS cohort. The ZP1 variants were inherited in an autosomal recessive pattern; the ZP2 and ZP3 variants were inherited in an autosomal dominant pattern. All variants were predicted to be deleterious. Studies in CHO cells suggested that most ZP1 variants led to increased intracytoplasmic protein and some variants influenced the intracellular transportation of other ZP proteins. Variant p.R642Q of ZP2 caused the secretion of ZP2 protein with an increased molecular weight, suggesting altered protein modification. Variant p.I619N of ZP2 resulted in increased ZP2 protein in cell lysate and decreased ZP2 protein in culture medium. These results showed that ZP variants might block the intracellular transportation and secretion of ZP proteins and disrupt the zona pellucida.

CONCLUSION(S)

We identified novel variants of ZP genes in more than half the cohort with GEFS and oocyte degeneration. Variants of ZP genes caused protein intracellular sequestration and failure to assemble the ZP filaments, resulting in EFS and female infertility. Our findings not only reveal the critical roles of ZP genes but also pave the way for the efficient genetic diagnosis of females with GEFS and oocyte degeneration.

Characteristics of Empty Follicular Syndrome during In vitro Fertilization Embryo Transfer and its Association with Various Etiologies in Comparatively Young Patients

Background:

Nearly 0.6%–7% of patients undergoing in vitro fertilization embryo transfer (IVF ET) will not be able to yield any oocyte despite successful ovarian stimulation and this condition is called as empty follicular syndrome (EFS). EFS is a dreadful situation for clinicians as well as patients, seems to be an unavoidable clinical condition despite a proper ovarian stimulation.

Materials and Methods:

This was a retrospective observational study conducted at a tertiary hospital; 1103 patients who underwent IVF ET between January 2016 and May 2017 were included in the study.

Study Outcome:

To estimate the incidence of empty follicle syndrome (EFS) and to study the associated factors.

Results:

There were 53 (4.8%) cases of EFS out of 1103 cycles of IVF ET; 43 (3.9%) cases were false EFS and 10 (0.9%) cases were genuine EFS. Mean age of EFS group and oocyte retrieved group was 30.17 years and 29.12 years respectively. Recurrence rate of EFS during the next IVF cycle was 36.8%. Decreased ovarian reserve was associated with an increased chance of EFS (54.7%) with a recurrence rate as high as 57%.

Conclusion:

The incidence of EFS is not an uncommon clinical scenario; it depends upon ovarian reserve to a great extent. Young age is not immune for the occurrence of EFS as there is a similar incidence in comparatively younger age group in our study. EFS is seen in all etiological groups of infertility, but only respite is that there is a chance of about 63.2% oocyte retrieval during repeat IVF cycle.

Successful Oocyte Retrieval, Fertilization, and Clinical Pregnancy with Low Serum β-hCG on the Day of Oocyte Collection: A Reappraisal of the Definition of the Empty Follicle Syndrome

Objective

To describe a case of successful oocyte retrieval, fertilization and clinical pregnancy despite very low β-hCG level, twelve hours after ovulation trigger.

Design

Case report. Setting. Academic medical center. Patient. A 38-year-old patient inadvertently administered 2,000 IU hCG for final oocyte maturation; serum hCG twelve hours later was 16 IU/L. Interventions. Effort to obtain and administer a booster dose of hCG over the next twenty-seven hours failed. Main Outcome. Successful oocyte retrieval.

Results

Fourteen oocytes were retrieved of which twelve were in metaphase II and nine fertilized after intracytoplasmic sperm injection (ICSI). Of these, eight embryos survived to day 5 and were subjected to preimplantation genetic screening (PGS) by comparative genomic hybridization (CGH). Results were available the next day, three of the embryos were euploid and one was transferred on day 6. Pregnancy was confirmed twelve days later and currently the patient has an ongoing singleton intrauterine pregnancy.

Conclusion

Reproductive Endocrinology and Infertility specialists should be aware that final oocyte maturation could occur following injection of a lower dose of hCG with excellent fertilization rate and embryo development.

Self-Detection of the LH Surge in Urine After GnRH Agonist Trigger in IVF-How to Minimize Failure to Retrieve Oocytes

Research question: Urine LH testing may be useful to confirm an LH surge after the GnRH agonist (GnRHa) trigger prior to oocyte retrieval in IVF. Design: A prospective cohort study, including oocyte donors undergoing ovarian stimulation, treated with a GnRHa trigger for final oocyte maturation. Urine LH testing was performed at home, 12 h after the GnRHa trigger. In the case of a negative result, serum LH and progesterone measurements were done that same day. Donors with no serum LH peak after trigger were re-scheduled using a dual trigger, with GnRHa and hCG. Results: Three hundred and fifty nine oocyte donors were included in the analysis. Three hundred and fifty six donors had positive urine LH tests, followed by oocyte retrieval. In one case, the LH test was positive, however, no oocytes were retrieved (false positive 1/356). Three LH tests were negative in urine: in one of these three cases, LH was tested again in blood, confirming an LH rise, consistent with an optimal response to the GnRHa trigger; in the other two cases, serum LH was <15 mUI/mL, after which the oocyte retrieval was re-scheduled for 36 h after an being re-triggered, resulting in the retrieval of 19 and 22 MII oocytes, respectively. Considering the cost analysis, it would be a significantly cost-saving strategy, as blood testing would have costed 14,840€ vs. only 185.5€ in urine LH kits. Conclusions: Urinary testing of the LH surge after GnRHa trigger is easy, safe, reliable, and convenient. In addition, LH urine testing allows identifying donors and patients who could benefit from a rescue hCG trigger after an unsuccessful GnRHa trigger.

Does the empty follicle syndrome occur in cases of low number of maturing follicles in assisted reproduction?

The pathophysiology of the genuine empty follicle syndrome (EFS) is still debated. Ovarian aging has been contested as a cause of this condition. Our aim was to investigate the occurrence of the genuine EFS in cases of a low number of mature follicles in a prospective manner. Ninety-five infertile women were recruited and evaluated following conventional controlled ovarian stimulation (COS) with ≤ six follicles of ≥14 mm diameter on the day of hCG administration. Enrolled women were 37.5 ± 5.2 years of age with basal FSH level of 9.1 ± 3.7 mIU/L, antral follicle count (AFC) of 6.9 ± 4.6, and number of ≥14 mm follicles (on the day of hCG) of 3.4 ± 1.5. Among the 95 women, four were complicated by the genuine EFS (4.2%) with features of the depleted ovarian reserve. Comparison between these four cases and the 91 controls revealed significant differences between age, AFC, number of ≥14 mm follicles, and serum E₂ level corresponding to 41.8 ± 1.7 versus 37.4 ± 5.2 years, 1.7 ± 0.6 versus 7.1 ± 4.5, 2.0 ± 0.8 versus 3.4 ± 1.5 follicles, and 356 ± 200 versus 975 ± 557 pg/mL, respectively. Post hoc analysis revealed that 56 among the 95 women fulfilled the Bologna criteria for poor ovarian response and all four cases matched the definition of the genuine EFS raising its incidence to 7.1% in this group. A logistic regression analysis showed that AFC was a significant factor in the development of the genuine EFS. We conclude that the genuine EFS complicates infertile women characterized by a low number of mature follicles. Our findings suggest that the mechanism behind this occurrence is associated with a more exhausted ovarian reserve.

Empty Follicle Syndrome: A Challenge to Physician

Background:

Empty follicle syndrome (EFS) is a condition in which no oocytes are retrieved from normally growing ovarian follicles after ovarian stimulation. It is a rare and frustrating condition of obscure etiology.

Objective:

The objective of this study was to estimate the incidence of EFS and study factors related to it.

Design:

This was a retrospective study.

Setting:

This study was conducted in hospital-based research center.

Methods:

In 1968 in vitro fertilization cycles from January 2010 to August 2016 were studied. Agonist, antagonist, and miniflare protocols were used for the stimulation.

Results:

The incidence of EFS is 2.38% (47/1968 cycles). Antagonist protocol group (76.59%, n = 36) had highest incidence of EFS (6.69%). Literature on EFS depicts decreased ovarian reserve (DOR) as the main cause, but only 4.25% of patients had DOR in our study. Interestingly, polycystic ovary syndrome and unexplained infertility were found in 31.9% of the cases. Serum anti-Müllerian hormone (AMH) levels (mean ± standard deviation [SD]) were 4.47 ± 3.54 ng/ml, and antral follicle count (AFC) was 15.30 ± 8.07 (mean ± SD) emphasizing that diminished ovarian reserve is not the main factor for EFS. All patients (n = 95) who underwent ovum pickup on day when any patient had EFS were taken as control. Patients with EFS were compared with controls. A statistically significant difference was not observed in serum AMH (P = 0.38) and AFC (P = 0.52).

Conclusion:

EFS is an uncommon event. Antagonist cycles have higher chances of empty follicle at ovum pickup. Looking at the profile of patients in this study, we conclude that EFS is not a manifestation of DOR.

Comparison of two different dosage of GnRH agonist as ovulation trigger in oocyte donors: a randomized controled trial

OBJECTIVE

To compare the results obtained with two different GnRH agonist dosages: 0.3mg versus 0.4mg to trigger ovulation in oocyte donor cycles.

METHODS

Experimental controlled randomized trial including 40 patients from a private practice center. The patients were randomized into two groups. Group A received a single dose of Triptorelin 0.3mg (Decapeptyl®) 36hours before pick-up. Group B patients received Triptorelin 0.4mg (Decapeptyl®) before pick-up to final oocyte maturation. We evaluated the total number of oocytes collected, the number of mature oocytes and total days of ovarian stimulation.

RESULTS

The average of total collected oocytes were 16 (Group A) versus 15 (Group B), and the mean number of mature oocytes were 13 versus 12 respectively. The only variable showing a difference was the percentage of mature oocytes, which was greater in Group A, resulting in 84.6%, in contrast with those treated with 0.4mg of Triptorelin (78.6%), although these differences were not statistical significant (p=0.35). Days of stimulation did not differ between groups. No cases of empty follicle syndrome were reported.

CONCLUSIONS

We found that an increase from 0.3 to 0.4mg of triptorelin in an oocyte donation program might not improve outcomes. Nevertheless, more studies might be necessary, not only in oocyte donors but in sterile women as well, to evaluate how GnRH agonist dosage could affect the results among other factors.

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.

Dual trigger for final oocyte maturation improves the oocyte retrieval rate of suboptimal responders to gonadotropin-releasing hormone agonist

OBJECTIVE

To identify the risk factors for suboptimal response to GnRH agonist (GnRH-a) trigger and evaluate the effect of hCG on the outcome of patients with suboptimal response to GnRH-a.

DESIGN

A retrospective data analysis.

SETTING

A tertiary-care academic medical center.

PATIENT(S)

A total of 8,092 women undergoing 8,970 IVF/intracytoplasmic sperm injection (ICSI) treatment cycles.

INTERVENTION(S)

All women underwent hMG + medroxyprogesterone acetate (MPA)/P treatment cycles during IVF/ICSI, which were triggered using a GnRH-a alone or in combination with hCG (1,000, 2,000, or 5,000 IU). Viable embryos were cryopreserved for later transfer.

MAIN OUTCOME MEASURE(S)

The rates of oocyte retrieval, mature oocytes, fertilization, and the number of oocytes retrieved, mature oocytes, and embryos frozen.

RESULT(S)

In total, 2.71% (243/8,970) of patients exhibited a suboptimal response to GnRH-a. The suboptimal responders (LH ≤15 mIU/mL) had a significantly lower oocyte retrieval rate (48.16% vs. 68.26%), fewer mature oocytes (4.10 vs. 8.29), and fewer frozen embryos (2.32 vs. 3.54) than the appropriate responders. Basal LH levels served as the single most valuable marker for differentiating suboptimal responders with the areas under the receiver operating curve of 0.805. Administering dual trigger (GnRH-a and hCG 1,000, 2,000, 5,000 IU) significantly increased oocyte retrieval rates (60.04% vs. 48.16%; 68.13% vs. 48.16%; and 65.76% vs. 48.16%, respectively) in patients with a suboptimal response.

CONCLUSION(S)

Basal LH level was useful predictor of the suboptimal response to GnRH-a trigger. Administrating dual trigger including 1,000 IU hCG for final oocyte maturation could improve the oocytes retrieval rate of GnRH-a suboptimal responder.

Empty Follicle Syndrome: The Possible Cause of Occurrence

OBJECTIVES

Empty follicle syndrome (EFS), although rare, is a disappointing condition in which no oocytes are retrieved from mature follicle after ovulation induction in in vitro fertilization (IVF) cycles. The aim of this study was to estimate the incidence and factors associated with EFS.

METHODS

All cycles resulting in EFS from May 2012 to September 2013 were retrospectively identified at a tertiary referral infertility center. Among the 3,356 cycles performed, 58 (1.7%) women who underwent their first IVF cycle and had no oocyte retrieval were enrolled in the study. Three different stimulation protocols (long, antagonist, and miniflare) were mainly used for induction of follicular growth. Data relating to the age, follicle stimulating hormone (FSH) level, anti-Müllerain hormone (AMH) level, and the number of ampules and follicles for each patient was obtained.

RESULTS

Out of 58 individuals, 10 (17.2%) showed false type and 48 (82.8%) showed genuine EFS. The most frequent findings in our study were diminished ovarian reserve, low anti-Müllerian hormone (AMH; ≤0.5 ng/mL), and less than four mature follicles, indicating EFS in 1.7% of the patients.

CONCLUSION

Low serum AMH levels and a small number of follicles after ovarian stimulation is the manifestation of diminished ovarian reserve. Thus, we suggest that EFS could be a manifestation of low ovarian reserve.

Empty follicle syndrome: Successful pregnancy following dual trigger

Empty follicle syndrome (EFS) is an uncommon, but the frustrating complication of assisted reproductive technology with failure to obtain oocytes after an adequate ovarian response to stimulation. Most of the reported cases of EFS are drug-related problems which are actually avoidable and do not represent any potential pathology and that the risk of genuine EFS (GEFS) is much smaller than was once thought. Our case is the first report of a pregnancy obtained after management of GEFS with dual trigger in a gonadotropin-releasing hormone (GnRH) antagonist cycle. In this report, we present a patient who underwent two oocyte retrievals, in which no oocytes were obtained. In the third in-vitro fertilization cycle, a dual trigger with the combination of GnRH agonist and human chorionic gonadotropin yielded 11 oocytes, which led to the transfer of 2 blastocysts resulting in a live birth. Changing the treatment protocol with dual trigger brought about a successful outcome.

Luteal phase ovarian stimulation following oocyte retrieval: is it helpful for poor responders?

BACKGROUND

Poor ovarian response and retrieval of no oocytes following ovarian stimulation for in vitro fertilization (IVF) is a challenging problem for both the patient and the clinician.

FINDINGS

Recent evidence indicates that folliculogenesis occurs in a wave-like fashion indicating that there are multiple follicular recruitment waves in the same menstrual cycle. This relatively new scientific concept provides new opportunities for the utilization of ovarian stimulation in women with poor ovarian response. This communication reports on the social and scientific rationale for the use of luteal phase ovarian stimulation following oocyte retrieval in the same cycle (also called double stimulation).

CONCLUSIONS

Data to date showed that double ovarian stimulation in poor responders provides shorter time for retrieving mature oocytes with the potential formation of good quality embryos, and thus healthy pregnancies.

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.

Recurrence of empty follicle syndrome with stimulated IVF cycles

AIM

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

METHODS

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

RESULTS

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.

CONCLUSION

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.

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.

The prevalence of genuine empty follicle syndrome

OBJECTIVE

To describe the prevalence of "genuine" empty follicle syndrome (EFS) and "false" EFS at assisted reproductive technology (ART).

DESIGN

Retrospective cohort.

SETTING

Large private fertility center.

PATIENT(S)

A total of 12,359 patients who underwent ART between 2004 and 2009.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The failure to recover an oocyte during oocyte retrieval at ART, with and without a detectable serum β-hCG on the day of retrieval.

RESULT(S)

Two cases of genuine EFS and nine cases of false EFS were identified in the cohort examined. The prevalence of genuine EFS was 0.016%, and the prevalence of false EFS was 0.072%. Only two out of 11 cases of EFS were considered genuine.

CONCLUSION(S)

Genuine EFS is a rare occurrence. Because this syndrome tends to recur with dismal pregnancy rates at ART, continued identification and further investigation of the syndrome are needed.

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.

[In Vitro Fertilization: beware of oocyte retrieval without oocyte!]

A 30-year-old woman undergoing an In Vitro Fertilization (IVF) treatment for tubal infertility and for whom no oocyte was retrieved at the puncture ("white puncture") presented an ectopic pregnancy. The patient was asymptomatic except some bleeding events reported for several days prior to the puncture. The ovulation monitoring was normal throughout the stimulation by gonadotrophin and hCG was administered for the final oocyte maturation on the twelfth day of stimulation at a rate of 2771 pg/ml of estradiol with a perfect ultrasound follicular growth. This case demonstrates that we have to beware of a "white puncture" and that the hCG measurement the day of the oocyte retrieval is necessary because of the possibility of an ectopic pregnancy.

Evidence of 'genuine empty follicles' in follicular aspirate: a case report

Failure to retrieve oocytes after normal ovarian stimulation has been labeled 'empty follicle syndrome' (EFS). The existence of genuine EFS has been questioned and is still controversial. Here, we report an unusual case in which an extraordinary number of empty follicle-like structures were identified in the ovarian aspirate at the time of retrieval. A 31-year-old woman presented with a 4-year history of primary infertility and underwent ovulation induction. The patient was given hCG and oocyte retrieval was performed 36 h later. During the oocyte retrieval, more than 200 tiny structures resembling pre-antral follicles were noted in the ovarian aspirate. They exhibited two to three layers of granulosa cells and appeared to enclose an immature oocyte. They showed a great variation in size ranging between 40 and 80 microm. These structures were further characterized by electron microscopy and cultivated in vitro to assess hormone secretion. The follicles were found to be devoid of oocytes, but each had a readily identifiable zona. Hormone assays revealed that these follicles were secreting increasing levels of estradiol. A second in vitro fertilization attempt gave similar results. These data are suggestive of some failure in the oocyte maturation process. We speculate that this may be the first actual evidence to support the existence of true empty follicles, which if left to grow in vivo might lead to empty graffian follicles and genuine EFS.

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.