Preliminary experience with human oocyte cryopreservation using 1,2-propanediol and sucrose

Effects of ovarian source, patient age, and menstrual cycle phase on in vitro maturation of immature human oocytes

OBJECTIVE

To determine the efficiency of in vitro maturation, expressed by nuclear maturation, of oocytes aspirated during gynecologic surgeries or collected from excised ovaries. To assess the effect of patient age and cycle phase at collection on the oocyte's ability to mature in vitro. To examine the time course of oocyte maturation in vitro.

DESIGN

Nuclear maturation based on patient criteria compared.

SETTING

University-based IVF program and research center.

PATIENT(S)

Consented patients undergoing gynecologic surgeries or patients undergoing oophorectomy.

INTERVENTION(S)

Oocytes were maintained in culture for 48 hours and evaluated for maturation.

MAIN OUTCOME MEASURE(S)

Nuclear maturation evaluated as germinal vesicle breakdown (GVBD) or progression to the metaphase II (MII) stage.

RESULT(S)

A significantly higher percentage of oocytes collected during the follicular phase of the menstrual cycle underwent GVBD than did oocytes collected during the luteal phase (60% versus 48%, respectively). The percentage of oocytes reaching the MII stage, from these two groups, was not different. No statistically significant differences in maturation were observed in oocytes from different ovarian sources or from patients >40 or <40 years of age.

CONCLUSION(S)

These data suggest that oocytes collected during the follicular phase are more likely to undergo GVBD than oocytes collected during the luteal phase. In this study, ovarian source, age, or cycle phase did not influence the final meiotic maturation of oocytes to metaphase II.

Preservation of fertility in women undergoing chemotherapy: current approach and future prospects

PURPOSE

Anticancer treatment causes ovarian failure.

METHODS

Some hormones may have a protective effect on the ovary. Cryopreservation (freezing) of oocytes has had very limited success, and therefore, currently its use before chemotherapy is not a feasible option. However, cryopreservation of embryos is possible. Another solution is oocyte donation followed by in vitro fertilization (IVF).

RESULTS

Ovarian cortical slices containing primordial follicles have been cryopreserved successfully. To restore fertility, cryopreserved-thawed tissue taken from cancer patients before therapy could be replanted after recovery. The possible risk of malignancy restoration could be eliminated by obtaining unilaminar follicles from cryopreserved-thawed tissue and growing them in vitro, followed by routine IVF.

CONCLUSIONS

Although women who undergo chemotherapy face limited options for fertility preservation, intensive studies in cryopreservation and in vitro maturation of follicles harbor hope for brighter prospects in the future.

Pregnancy after human donor oocyte cryopreservation and thawing in association with intracytoplasmic sperm injection in a patient with ovarian failure

OBJECTIVE

To describe a pregnancy after human donor oocyte cryopreservation in association with intracytoplasmic sperm injection in a patient with ovarian failure.

SETTING

Department of Reproductive Medicine, CER Medical Institute, Buenos Aires, Argentina.

PATIENT

A 48-year-old patient with ovarian failure.

RESULTS

Ten donated oocytes were cryopreserved. Survival after thawing was 30%. Three oocytes were microinjected, and two embryos were obtained. The fertilization rate was 66%, and embryo development was 100%. Both embryos were transferred to a patient who had received hormonal replacement therapy. The attempt was successful, and a pregnancy was achieved after the transfer.

CONCLUSION

In association with intracytoplasmic sperm injection, an adequate technique of freezing and thawing of human oocytes might achieve encouraging results in ART programs.