Predicting empty follicle syndrome**Presented at the 15th World Congress on Fertility and Sterility, Montpellier, France, September 17 to 22, 1995

Factors associated with oocyte recovery rates during in-vitro fertilization among Nigerian women

Introduction

the availability of oocytes is fundamental to in vitro fertilization (IVF). The factors associated with optimal or suboptimal oocyte recovery rates (ORR) in low-resource settings are not well known. This study aimed to determine the factors associated with ORR by comparing demographic and IVF cycle data of women undergoing IVF in our Centre.

Methods

this was a prospective study of 110 infertile women undergoing IVF at Nisa Premier Hospital, Abuja Nigeria, from October 2020 to September 2021. All women had reached the stage of oocyte retrieval or further, after receiving ovarian stimulation with our routine protocols. Treatment was monitored by serial transvaginal ultrasonography. The oocyte retrieval procedures were performed under conscious sedation, 36 hours after the ovulatory trigger. Optimal ORR was when eggs were obtained from at least 80% of follicles punctured. Sub-optimal ORR was when it was less than 80%. Data analyses utilized SPSS statistical software and a p-value of < 0.05 was considered significant.

Results

the mean age of all women was 34.1±4.9 years. Sixty-nine women (62.7%) had sub-optimal ORR while 41 (37.3%) had optimal ORR. Six women (5.5%) had no oocytes retrieved. Significantly more women with sub-optimal ORR were obese (70.6 vs 29.4%) and had higher follicle-stimulating hormone (FSH) levels (8.11 vs 6.34 miu/ml), p-value- 0.039. Women with sub-optimal ORR had higher mean prolactin levels (17.10 ± 13.93 miu/ml) than women with optimal ORR 11.43 ± 6.65 miu/ml), p-value- 0.019). Significantly more oocytes (5.99 vs 10.37, p-value 0.001), and MII oocytes (5.78 vs 7.56, p-value 0.035) were retrieved in women with optimal than sub-optimal ORR. The duration of stimulation, total amounts of gonadotropins administered, and fertilized oocytes were not significantly different among both groups (p-value >0.05).

Conclusion

this study has shown the factors associated with ORR in our setting to be basal FSH, prolactin, and obesity.

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.

A borderline form of empty follicle syndrome treated with a double-trigger of gonadotropin-releasing hormone agonist and human chorionic gonadotropin: A case report

RATIONALE

The borderline form of empty follicle syndrome (EFS) is a phenomenon where only a few mature or immature oocytes are retrieved despite adequate response to controlled ovarian hyperstimulation (COH). It is a rare phenomenon with an unclear underlying mechanism, and there is currently no effective treatment.

PATIENT CONCERNS

The patient received 3 assisted reproductive technology cycles, and although her follicular development and estrogen levels were normal during COH, the outcome with respect to the oocytes obtained was unsatisfactory.

DIAGNOSES

Borderline form of EFS.

INTERVENTIONS

In the context of undergoing GnRH-antagonist protocol, we implemented a double-trigger with human chorionic gonadotropin (hCG) after 6 hours of gonadotropin-releasing hormone agonist (GnRH-a) administration.

OUTCOMES

Eleven oocytes were obtained (M I × 3, M II × 8), which underwent in vitro fertilization (IVF). After 18 hours, 7 oocytes showed normal fertilization, with 2 embryos formed 72 hours later (embryo rating, 6C II × 1, 9C II × 1); the embryos were then frozen.

LESSONS

Oocyte maturation and ovulation are time-dependent processes, and that different patients require different lengths/intervals of time for treatment. Therefore, the borderline form of EFS, in general, may be treatable, and our novel trigger method provides a new treatment option for such patients in the future.

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.

A case of empty follicle syndrome who conceived after aspiration of an endometrial cyst

Empty follicle syndrome (EFS) has been defined as a condition where no oocytes can be retrieved for in vitro fertilization (IVF) even though ultrasound findings and estradiol (E₂) levels suggest the presence of potential follicles. The EFS is a rare condition with an incidence of 0.5-7 % of women undergoing IVF treatments. Although there are many hypotheses as to the cause of EFS, including advanced ovarian age, drug-related problems, and dysfunctional folliculogenesis, its cause remains unknown. A 37-year-old woman with endometriosis and a 5-year history of primary infertility underwent IVF treatment for 4 cycles. No oocytes were retrieved in 2 cycles and no fertilized eggs were obtained in the other 2 cycles. We assumed that endometriosis adversely affected folliculogenesis and fertilization. Aspiration of an endometrial cyst in the right ovary and subsequent administration of oral contraceptives resulted in successful folliculogenesis and fertilization. Thereafter, she conceived and delivered a 2,662 g female infant at 38 weeks of gestation. Here, we report a case of EFS who conceived in the 5th IVF cycle after aspiration of an endometrial cyst. We assumed that endometriosis might have been involved in the dysfunction of folliculogenesis and EFS.

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.

Inherited mutation of the luteinizing hormone/choriogonadotropin receptor (LHCGR) in empty follicle syndrome

OBJECTIVE

To test by genomic analysis whether empty follicle syndrome (EFS) in a family with two affected sisters has a genetic basis.

DESIGN

Whole-exome sequencing in the context of clinical genetics.

SETTING

University hospital.

PATIENT(S)

Two women (36 and 32 years old at the time of the study) with EFS.

INTERVENTION(S)

Genetic counseling based on autosomal recessive inheritance.

MAIN OUTCOME MEASURE(S)

Discovery of a mutation in the LH/choriogonadotropin receptor (LHCGR) as the cause of EFS.

RESULT(S)

A novel missense mutation in LHCGR, p.N400S, was homozygous in sisters with EFS and/or infertility, but not in their unaffected siblings or parents. The mutation was not present in 500 ancestry-matched control subjects. Asparagine at residue 400 is highly conserved and its substitution by serine predicted to alter critical interactions that stabilize LHCGR.

CONCLUSION(S)

We describe a genetic basis for EFS and provide strong evidence for the existence of genuine EFS in some patients. A mutation impairing the function of LHCGR explains the lack of response of these patients to repeated administration of β-hCG.

Influence of body mass index and self-administration of hCG on the outcome of IVF cycles: a prospective cohort study

Final maturation of the oocyte in in vitro fertilization (IVF) cycles is achieved through the administration of a timed injection of human chorionic gonadotrophin (hCG). The success of mature oocyte retrieval is dependent on serum concentrations of the hormone reaching values capable of initiating meiosis and triggering the release of the cumulus-oocyte complex into the follicular fluid. The objective of this prospective cohort study was to examine the effect of adiposity, as measured by body mass index (BMI), on serum concentrations of hCG and gonadotrophins and to relate this to IVF outcome. A comparison was also made between professionally and non-professionally administered hCG to assess any possible effect on cycle parameters. A total of 50 patients with a high BMI (> or = 26 kg m(-2)) who underwent IVF treatment at the Assisted Conception Unit, St James's University Hospital, Leeds, was recruited prospectively into the study. They were matched with 50 patients with a normal BMI (18-25 kg m(-2)) who acted as a control group. The two groups were matched for age (mean of 32 years and range of 22-42 years) and cause of infertility. Serum gonadotrophins, oestradiol and hCG concentrations, measured at the time of oocyte retrieval, and the clinical outcome of the two groups were compared. Patients with a high BMI had a significantly lower mean serum hCG concentration compared with controls (63.9 versus 99.6 iu l(-1), P < 0.0003). They also required a higher dosage of gonadotrophin (3660 versus 3007 iu) to achieve follicular maturation than the controls. Similarly, the high BMI group of patients had higher serum concentrations of follicle-stimulating hormone (FSH) (12.3 versus 11.2 iu l(-1)) and lower oestradiol (3499 versus 3506 pmol l(-1)) compared with controls. Patients with a high BMI had significantly fewer oocytes aspirated, resulting in a significant decrease in the oocyte:follicle ratio compared with controls (33.9 versus 41.7, P < 0.05). The fertilization rate (46.2 versus 61.3%, P < 0.05) and clinical pregnancy rate per cycle (26.6 versus 37.1%, P < 0.05) were also lower in the patients with high BMI compared with those with normal BMI. The administration of hCG by the patient or her partner did not have a significant effect on clinical outcome. The mean serum hCG at the time of oocyte recovery was equivalent in both groups (87.1 versus 89.7 iu l(-1)). Furthermore, the oocyte:follicle ratio (0.73 versus 0.72), fertilization rate (46.2 versus 54.2%) and clinical pregnancy rate (38.9 versus 36.5%) were similar. These findings indicate that high BMI is detrimental to the success of IVF treatment and has an important influence on the distribution and metabolism of hCG. The results also indicate that non-professional administration of hCG does not compromise cycle outcome.

Relationship between serum human chorionic gonadotrophin levels and body mass index in women undergoing in vitro fertilisation cycles

OBJECTIVE

To ascertain if serum concentrations following injection of human chorionic gonadotropin (hCG) influenced the outcome of in vitro fertilisation (IVF) treatment and correlated to body mass index (BMI).

STUDY DESIGN

A prospective study conducted with the participation of 149 women undergoing IVF and/or intracytoplasmic sperm injection (ICSI) treatment at the regional IVF Unit in Liverpool, UK. The BMI of each individual was calculated and serum hCG concentrations were measured at 12 and 36 h following a subcutaneously (SC) injection of 5000 IU hCG. The main outcome measures were fertilisation rate and biochemical pregnancy rate.

RESULTS

No correlation was found between serum hCG levels at 12 and 36 h with the number of oocytes retrieved or the number of oocytes fertilised. Furthermore, there was no correlation between BMI and hCG levels at 12 and 36 h following administration (Pearson's correlation coefficient: -0.23, -0.24, respectively).

CONCLUSION

Our results suggest that the serum concentrations of hCG do not influence IVF outcome and that the serum levels of hCG achieved following administration do not correlate with the individual's BMI. Serum hCG concentration also does not correlate with number of oocytes collected or fertilisation rate.

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.

Poor oocyte retrieval is a manifestation of low ovarian reserve

Women with complete absence of oocytes during retrieval, as well as those with less than the 10th percentile of the expected number of oocytes retrieved, have clear manifestations of low ovarian reserve. It seems that this occurrence is a gradual biological phenomenon related to the basic pathophysiology of ovarian aging.

Is the occurrence of the empty follicle syndrome a predictor that a subsequent stimulated cycle will be an unfavourable one?

Several hypotheses have been advanced to explain empty follicle syndrome (EFS) but it remains a controversial topic. This paper reports experience with three IVF cycles in which no oocytes were collected. In all cases, an additional IVF cycle was performed. The ovarian stimulation protocol, ultrasound and hormonal surveillance methods, human chorionic gonadotrophin timing and oocyte retrieval technique were similar in all patients. The assessment of additional cycles demonstrated a poor response in terms of oocyte quality, since the number of mature oocytes was low despite the high number of oocytes collected. Thus, the data suggest that in these patients, EFS should be considered as a borderline form of poor response to ovarian stimulation. If this is confirmed, EFS should be a recurrent event and an empty cycle could be a good predictor that a subsequent stimulated cycle will be an unfavourable.

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.

Borderline form of empty follicle syndrome: is it really an entity?

We report two patients who were administered erroneously 1000 IU HCG instead of 10,000 IU for ovulation triggering in an assisted reproductive technology (ART) cycle. In one case no oocyte was retrieved from eight mature follicles after several washing attempts and retrieval day serum beta-HCG level was 21 mIU/ml. As there was no follicle in the other ovary we did not try a rescue protocol. In the other case two immature and one mature oocytes were retrieved from 15 mature follicles located in both ovaries. Retrieval day serum beta-HCG level was 12 mIU/ml. ICSI was performed in one mature and two in vitro maturated oocytes and the embryo transfer that was done 72 h after the retrieval yielded a healthy singleton pregnancy. Our experience shows that a borderline form of EFS may be an entity and it may be possible to see the formation of periovulatory events and even to obtain a pregnancy in an ART cycle where the ovulation was triggered by 1000 IU HCG.

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.