Empty follicle syndrome: an entity in the etiology of infertility of unknown origin, or a phenomenon associated with purified follicle-stimulating hormone therapy?

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: 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.

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.

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.

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.

Double oocyte aspiration may be a solution for empty follicle syndrome: case report

OBJECTIVE

To assess the possibility of salvaging the cycle in a case of empty follicle syndrome by scheduling a second retrieval.

SETTING

Miami IVF/Intracytoplasmic Sperm Injection Center, Alexandria, Egypt. It is a private center.

PATIENT(S)

A 24-year-old female with a 6-year history of primary infertility. Intracytoplasmic sperm injection was performed because of her partner's obstructive azoospermia. No oocytes could be retrieved despite normal ultrasonic and hormonal responses and the presence of 25 mature follicles.

INTERVENTION(S)

Serum hCG on the day of the first retrieval. A second dose of hCG was given after the first retrieval, and a second retrieval was scheduled 24 hours later.

MAIN OUTCOME MEASURE(S)

Number of oocytes retrieved, fertilization and cleavage rates, and pregnancy outcome.

RESULT(S)

Serum beta-hCG level on the day of the first retrieval was 300 IU/mL. Eleven oocytes were retrieved, (7 were metaphase II, 3 fertilized, and 2 cleaved) and two embryos were transferred. No pregnancy resulted.

CONCLUSION(S)

In a variant of empty follicle syndrome, the cycle could be salvaged by giving another dose of hCG and scheduling another retrieval 24 hours later.

Estradiol, progesterone and androstenedione content of follicular fluids in 'empty follicles'

In an in vitro fertilization (IVF) and embryo transfer program with human menopausal gonadotropin/human chorionic gonadotropin treatment no oocytes were recovered in 18 out of 788 cycles. Estradiol (E2), progesterone (P) and androstenedione contents of 27 follicles obtained from five of the 18 patients were radioimmunologically measured and P:E2 ratio calculated. Control values of 20 follicles were obtained from four of these five patients in subsequent IVF cycles. A total of 17 oocytes were harvested. Estradiol, progesterone and androstenedione mean +/- SEM values (nmol/l) were, respectively, 4246 +/- 1484, 3751 +/- 1768 and 1920 +/- 641 in the failed cycles and 2504 +/- 908, 13,678 +/- 4749 and 509 +/- 87 in the successful ones. P:E2 ratios were 0.88 +/- 1.03 and 5.67 +/- 1.70, respectively. The differences in these levels of progesterone, androstenedione and the ratios of P:E2 were significant (p < 0.01). It is concluded that the probable cause of 'empty follicles' is inappropriate luteinization and they are not characteristic for a given patient or for stimulation with human menopausal gonadotropin/human chorionic gonadotropin.

Failed oocyte retrieval after lack of human chorionic gonadotropin administration in assisted reproductive technology

OBJECTIVE

To document the absence of oocytes in follicular aspirates in women who, during controlled ovarian stimulation with gonadotropin-releasing hormone agonist (GnRH-a) and menotropins, fail to receive human chorionic gonadotropin (hCG) administration.

DESIGN

Retrospective analysis of clinical laboratory data.

SETTING

Multicentric.

PATIENTS

Five women undergoing controlled ovarian hyperstimulation with GnRH-a and menotropins for programs of assisted reproductive technologies.

RESULTS

The documented absence of an hCG injection produced "empty follicles" at transvaginal guided aspiration, despite numerous follicular lavages and aspiration of peritoneal fluid. The lack of oocytes and granulosa-cumulus complex in the follicular fluid was reverted in other cycles in the same patients when hCG was properly administered.

CONCLUSIONS

(1) This study emphasizes the importance of proper patients' and nurses' instructions for preparation of hCG injections and proper mixture of vehicle and powder before follicular aspiration. (2) In the absence of cumulus-corona-oocyte complex at aspiration, measure serum beta-hCG to ascertain whether hCG injection was administered or not. (3) Routine preoperative beta-hCG levels may be helpful to avoid unnecessary surgeries.

Hormone levels of follicular fluids with and without oocytes in patients who received gonadotropin-releasing hormone analogues and gonadotropins in an in vitro fertilization program

BACKGROUND

Are follicles where no oocytes are retrieved "empty follicles"?

METHODS

The levels of estradiol (E2), progesterone (P), testosterone (T), cortisol (F), and prolactin (PRL) of follicular fluids (FF) aspirated individually from 34 randomly selected IVF patients in whom no oocytes were recovered were compared with the respective hormone levels of FF obtained from the same patients when oocytes were retrieved. Two FF without oocytes of a 35th patient in whom no oocytes were retrieved were analyzed.

RESULTS

Hormones did not differ significantly in the paired samples, while in the two FF of the 35th woman they were in agreement with cystic follicles.

CONCLUSIONS

It is necessary to differentiate aspirated follicles where no oocytes are retrieved from the "empty follicle syndrome," which was not observed in the IVF series studied and should be rare in IVF patients.

Failure of oocyte retrieval during in vitro fertilization: a sporadic event rather than a syndrome

Failure to retrieve oocytes during in vitro fertilization (IVF) treatment was recently referred to as the "empty follicle syndrome." Data on the possible repetitiveness of this during previous or subsequent IVF attempts is lacking, which limits the understanding of its significance to the involved patients. Of 26 patients who had cycles during which no oocytes were retrieved, 10 were pregnant in the past and 20 had at least one other IVF cycle that yielded oocytes. There was no difference in the frequency of any stimulation protocol among the failure cycles compared with the successful ones. Hormonal response pattern and the number of large follicles observed sonographically did not differ between the two occasions. Fertilization occurred in 70% of the successful cycles and two biochemical pregnancies were recorded. In 13 patients, at least one cycle was canceled because of poor ovarian response, but 9 of these 13 had at least one other successful cycle. We conclude that the so-called empty follicle syndrome cannot be predicted by the pattern of ovarian response and does not predict a reduced fertility potential in future cycles.

Anomalies of human oocytes from infertile women undergoing treatment by in vitro fertilization

During in vitro fertilization treatment, three types of oocyte anomalies were observed in four infertile women. These anomalies were related to (1) failure of oocyte maturation from the germinal vesicle stage of meiosis, (2) failure of polar body formation and cleavage, and (3) absence of oocytes in otherwise mature follicular aspirates. These anomalies are considered to contribute to these patients' infertility.

Ovarian stimulation with pure follicle-stimulating hormone/human menopausal gonadotropin and improved laparoscopic aspiration needles influence the success of an in vitro fertilization program

The effect of a combined pure follicle-stimulating hormone/human menopausal gonadotropin (pFSH/hMG) ovarian stimulation regimen and modified, sharpened laparoscopic follicular aspiration needles on the number of oocytes retrieved and the oocyte/follicle ratio in 43 consecutive cycles of in vitro fertilization (IVF) were retrospectively compared with 99 consecutive preceeding cycles stimulated with hMG alone and captured with aspiration needles that had never been sharpened. A modified laparoscopic follicular aspiration needle is described. Purified FSH/hMG ovarian stimulation significantly improved the mean serum estradiol levels, number of preovulatory follicles, and, therefore, the total number of oocytes recovered per cycle. The mean ratios of oocytes recovered per preovulatory follicle documented on ultrasound, and per aspirated follicle, increased significantly using sharpened needles. Both modifications improved the success rate of our IVF program.