Giuseppe Damiano

Clinical experience and applications of oocyte cryopreservation

Oocyte cryopreservation is a viable solution for the ethical problems related to embryo storage, and the only available technique for preservation of fertility in women who have to undergo chemo- or radiotherapy. The main problems with oocyte cryopreservation are concerned with the survival rate and the fertilization rate. Recently the introduction of the intracytoplasmic sperm injection (ICSI) led to an increase in the fertilization rate. The success achieved with the first case treated encouraged us to set up a clinical trial on human oocyte cryopreservation. In the first stage of the study, 23 women with tubal infertility were enrolled. Superovulation was induced and 375 oocytes were retrieved; of these 338 oocytes were frozen. The survival rate was 59.5% and was independant of the duration of cryopreservation or the presence of cumulus. The normal fertilization rate was 64.4%, and only 7.5% of fertilizations were abnormal. A total of 90.8% of fertilized oocytes cleaved. A mean of 3.1+/-1.3 embryos per patient were transferred. Three pregnancies were achieved. In the second stage of our investigation, more patients were enrolled and similar results were observed. Sixteen pregnancies were achieved. A further stage of the investigation involved the fertilization of frozen oocytes with frozen sperm and even these resulted in a pregnancy. Our study demonstrated that pregnancies can also be achieved when frozen eggs are fertilized by testicular and epididymal sperm. As a consequence of the success of our investigations, a program of oocyte cryopreservation for oncological patients has been initiated in our centre. In our opinion, oocyte cryopreservation is, at present, a safe and efficient technique as documented by the birth of several healthy children.

Healthy twins delivered after oocyte cryopreservation and bilateral ovariectomy for ovarian cancer

Anti-neoplastic treatments have significantly increased the survival of cancer patients, but female patients risk premature menopause. Oocyte cryopreservation has been proposed as a fertility-saving option. This report describes the first live birth achieved with autologous cryopreserved oocytes in an ovariectomized borderline cancer patient. A patient with a borderline ovarian tumour asked for oocyte cryopreservation after a right adnexectomy. Ovulation induction resulted in the retrieval and cryopreservation of seven mature oocytes. Thirty-nine months after a left ovariectomy, the patient asked for oocyte thawing and embryo transfer. Endometrial growth was induced using hormone replacement treatment. Three of the seven cryopreserved oocytes were thawed; they survived and, after insemination, normal fertilization took place. Three embryos were transferred into the patients uterus. A twin pregnancy was achieved with the birth of two healthy females. Oocyte cryopreservation may be a reliable option for preserving fertility in young cancer patients who risk premature menopause due to surgery, chemotherapy or radiotherapy.