Follow-up of ovarian function post-chemotherapy following ovarian cryopreservation and transplantation.

BACKGROUND: The purpose of this study was to assess the ovarian function after treatment of a malignant disease in women who previously had cortical tissue from an entire ovary cryopreserved prior to chemotherapy, and to assess ovarian function after autotransplantation of cryopreserved ovarian tissue. All were treated with chemotherapeutic drugs with an estimated high risk of inducing ovarian failure. METHODS: Twenty-two women with breast cancer (n = 8), Hodgkin's disease (n = 6), non-Hodgkin's (n = 2), leukaemia (n = 5) or brain tumour (n = 1) underwent a clinical examination >18 months after cryopreservation. Three patients with premature ovarian failure had ovarian tissue autotransplanted orthotopically and heterotopically. Ovarian function was assessed by ultrasonography of the remaining ovary and hormone measurements. RESULTS: Nine of 22 women (41%) had sonographic and hormonal signs of ovarian failure with ovarian volumes <1.3 cm3, no antral follicles and high FSH levels (median 57.1 IU/l). Thirteen of the 22 women (59%) still menstruated and 10 had a seemingly normal ovarian function, with a median ovarian volume of 6.8 cm3, a median number of antral follicles of six, FSH <15 IU/l and normal estradiol levels. All three patients with autotransplanted ovarian tissue regained ovarian function as confirmed by return of menses, follicles on ultrasonography and normalized hormone levels. Two embryos were created from the crypreserved tissue after IVF. CONCLUSIONS: Treatment with bone-marrow transplantation and/or high doses of alkylating agents led to ovarian failure in all patients. Autotransplantation of ovarian tissue led to return of ovarian function.

Anti-Müllerian hormone initiates growth of human primordial follicles in vitro.

Survival and growth of follicles in human ovarian tissue is presently only performed with limited success. We evaluated the effect of anti-Müllerian hormone (AMH) and/or testosterone on follicular growth during a 4-week culture period using ovarian cortical tissue from six women in their reproductive years. The cortex of each biopsy was isolated and immediately cryopreserved upon collection and stored in liquid nitrogen. After thawing the tissue was placed in culture. After the culture period all follicles were counted on histological sections and classified for viability and stage of development. Based on evaluation of 6603 follicles it was found that the number of growing follicles significantly increased during the culture period as compared to the uncultured control, irrespective of the composition of the culture medium. Furthermore, significantly more follicles advanced to the primary and secondary stage (p<0.05) in tissue cultured with AMH (54%) as compared to tissue cultured in control medium (41%). The mean diameter of follicles classified as primary follicles was significantly enhanced in tissue cultured in the presence of AMH (p=0.002) and AMH plus testosterone (p<0.001) as compared to that observed in tissue cultured with control medium and medium containing testosterone alone. In contrast the mean diameter of the oocyte and its nucleus remained similar irrespective of culture medium. In conclusion, AMH seems to affect early stages of human follicular development by enhancing recruitment, survival and/or growth during a 4-week culture period.

Embryo quality in natural versus stimulated IVF cycles.

BACKGROUND: The impact of controlled ovarian stimulation (COS) on oocyte and subsequent embryo quality remains controversial. In the present study we have compared embryo quality in natural and stimulated cycles in the same group of patients. METHODS: This retrospective study was comprised of patients with a regular menstrual cycle who had IVF after COS using rFSH in a long GnRH agonist protocol. In all stimulated cycles the patients had fresh embryos transferred and surplus good quality embryos cryopreserved. Subsequently the same patients were treated with a modified FER cycle (mFER) where thawing of the frozen embryos was combined with aspiration of the dominant follicle in the natural cycle. The embryo cleavage stage and quality score were compared between the stimulated and the natural cycle for the patients having an embryo in the natural cycle. RESULTS: In 177 cases patients returned for mFER in a natural cycle. Spontaneous ovulation had occurred in 35 cycles. In 17 cycles no oocyte was retrieved at aspiration and in 125 cycles 128 oocytes were aspirated. In the stimulated cycles from these patients we had obtained 950 embryos (cleavage rate 70.4%) versus 85 embryos (cleavage rate 66.4%) (P = 0.34) in the natural cycles. Comparing the embryos in the natural and stimulated cycles in all patients having an embryo in the natural cycle, we found no difference in the distribution between the different cleavage stages. Of the cleaved embryos, 53% in the stimulated cycles had >or=4 cells versus 59% in the natural cycles after 2 days culture (P = 0.31). In the stimulated cycles 61% of the embryos had <10% fragmentation at the time of transfer on day 2, compared to 69% in the natural cycles (P = 0.15). CONCLUSION: The administration of exogenous gonadotrophins was not reflected in cleavage capacity or quality assessment of the resulting embryos.

Survival of primordial follicles following prolonged transportation of ovarian tissue prior to cryopreservation.

BACKGROUND: Cryopreservation of ovarian tissue for fertility preservation is becoming increasingly common. Treatment of diseases that may deprive the ovaries of follicles is often performed at local hospitals that are without the necessary facilities and expertise to cryopreserve ovarian tissue. The aim of the present study was to evaluate whether primordial follicles of ovarian cortex survive transport for up to 4 h prior to cryopreservation. METHODS: Immediately after recovery of one ovary from each of four patients, the cortex was roughly isolated, placed in IVF culture medium, kept on ice and transported for 3-4 h to the centre where final dissection and cryopreservation took place. Transplantation of pieces of thawed ovarian cortex under the skin of ovariectomized immunodeficient mice for a period of 4 weeks was used to assess the survival of primordial follicles. RESULTS: After transplantation, ovarian tissue from each of the four patients contained surviving follicles. CONCLUSIONS: Transport of roughly isolated ovarian cortex cooled on ice for a period of up to 4 h allows survival of primordial follicles following cryopreservation and transplantation to immunodeficient mice.

Density and distribution of primordial follicles in single pieces of cortex from 21 patients and in individual pieces of cortex from three entire human ovaries.

BACKGROUND: At the time of cryopreservation of ovarian tissue for fertility preservation a small biopsy of ovarian cortex is usually taken for histological evaluation of the follicular reserve. The purpose of this study was to evaluate the distribution and density of primordial follicles in single pieces of cortex from individual patients and in pieces of cortex comprising entire ovaries, all prepared for cryopreservation. METHODS: Cortical biopsies from 21 patients and the whole cortex of one ovary were evaluated histologically prior to cryopreservation. In addition, the cortex of two whole ovaries was cryopreserved before histological evaluation. The volume of each cortical fragment was measured, all follicles counted and the follicular density calculated. RESULTS: In individual pieces of cortex follicular density showed a significant inverse linear correlation with age. The follicular density per cortical fragment prepared from each of the three entire ovaries varied from 1.8 to 166, 0.007 to 140 and 0.04 to 4.48 follicles/mm(3) cortical tissue. CONCLUSION: The density of primordial follicles varied more than two orders of magnitude in cortical fragments from each of the three ovaries. Primordial follicles were very unevenly distributed throughout the cortex of these ovaries, although a significant linear correlation between age and follicular density was found.