Oocytes retrieval and cryopreservation for unmarried cancer female patients

Abstract

Aggressive chemotherapy and radiotherapy in unmarried cancer patients have greatly enhanced the life expectancy of the patients, but these treatments cause infertility because of the massive destruction of the ovarian reserve resulting in secondary amenorrhea. Ooocytes cryopreservation in these patients can be maintained their fertility after cancer treatment. We applied a minimal stimulation protocol using clomiphene citrate (CC) to be retrieved oocytes, and the cryotop vitrification method to cryopreserve oocytes for the patients. Retrospective analysis study. Eighty unmarried cancer patients with informed consent who underwent the CC cycle from January, 2001 to April, 2007. Fifty mg CC was administered from cycle day 3 and 75 IU HMG was administered every other day from day 8 until the leading follicle developed to 18 mm in diameter. Administration of CC was then stopped, and 300 μg GnRH-agonist (buserelin) was given as a maturation trigger. Oocytes were retrieved from 30 to 36 hrs following the administration of the GnRH-agonist using 21gauge needle without anesthesia (Teramoto, 2006). The retrieved oocytes were denuded before vitrification. The cryotop method (Kuwayama 2005) was used to vitrify the oocytes. The oocytes were equilibrated in 7.5% ethylene glycol and 7.5% DMSO in modified medium 199 (M-199) for 15 min before being transferred into the vitrification solution (VS) for 30 sec. After replacing the extracellular solution by pipetting, oocytes were then transferred into the vitrification container with minimum volume of VS, and immediately submerged into liquid nitrogen. The mean age of the patients was 29.3 ( ± 6.6, S.D.). The mean numbers of oocytes retrieval cycles per patient was 1.5. The mean numbers of retrieved oocytes per patient and per cycles were 4.4 and 3.0. The mean numbers of cryopreserved oocytes per patients and per cycles were 4.1 and 2.8 that had morphologic normally. Types of cancer that patients had were acute leukemia, chronic leukemia, malignant lymphoma, aplastic anemia, myelodysplastic syndrome, breast cancer, ovarian cancer, uterine cervix cancer et al. There were no significant difference of mean numbers of retrieved (3.4 to 8.5 per patients) and cryopreserved oocytes (3.3 to 6.1 oocytes per patients) in each cancer groups. Our data showed the possible use of the CC cycles and the cryotop methods for the maintenance of fertility of the unmarried patients after cancer treatments by cryopreservation.