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.

In vitro follicular development of cryopreserved mouse ovarian tissue.

In a previous report, we showed that follicles isolated from frozen/thawed mouse ovarian tissues reached the mature follicle stage on the 12th day of culture. However, the developmental ability was lower than that of fresh ovarian tissue. The purpose of this study was to define a culture system with some technical modification for preantral follicles isolated from frozen/thawed ovarian tissue and to confirm cell injury. Ovaries obtained from three-week-old female mice were cryopreserved by the rapid freezing method. Preantral follicles isolated from frozen/thawed ovarian tissues were cultured for 12-16 days. The follicles were then stimulated with human chorionic gonadotropin. In vitro fertilization was performed on the released cumulus-oocyte complexes (COCs). Preantral follicle viability was assessed by supravital staining using Hoechst 33258. Using this stain cell death was found in part of the granulosa cells of a follicle obtained from frozen/thawed ovarian tissue. On the 14th and 16th days of culture, the diameters of follicles isolated from frozen/thawed ovaries were larger than on the 12th day of culture. The released COCs were fertilized and developed to the blastocyst stage in 15.8% (12/76) of the oocytes taken from the fresh group, and in 0% (0/73), 2.9% (2/69) and 19.1% (22/115) of the oocytes taken from the frozen/thawed group that had been cultured for 12, 14 and 16 days respectively. The preantral follicles isolated from frozen/thawed mouse ovarian tissues developed slowly compared with the freshly prepared preantral follicles. During prolonged culture from 12 to 16 days, these follicles obtained the potential to fertilize and develop to the blastocyst stage.

Establishment of a novel method for cryopreservation and thawing of the mouse ovary.

During cryopreservation of ovarian tissue, the conditions of freezing and thawing are big factors controlling the survival rate of oocytes obtained. However, the conditions and procedures as they pertain to ovarian follicles and oocytes have not been established. Thus, we tried to determine the appropriate freeze-thaw times using the vitrification method with ethylene glycol and DMSO as cryoprotective agents and dd Y female mouse ovaries. The maturity rate from GV to the metaphase-II (MII) stage was 62.8% with ethylene glycol and 69.3% using DMSO, while the controls (GV oocytes obtained from a fresh ovary) showed a maturation rate of 83.6% (46/55). MII oocytes obtained by culturing GV oocytes in vitro showed a 64.3% (18/28) fertility rate via in vitro fertilization and a developmental rate into a 2 cell stage embryo of 35.7% (10/28) and into a 4-cell stage, 7.1% (2/28). However, development beyond the 8 cell stage embryo was not observed. A significant difference was not recognized between control (fresh) and ovarian tissues that had been frozen/thawed with respect to their ability to produce hormones. It is concluded that the vitrification method was effective for both freezing ovarian tissues and preserving its functional ability (maturation and capacitation).