Background: In vitro maturation (IVM) is a culture technology that enables the immature oocytes to reach metaphase II (MII). Vitrification of immature oocytes followed by in vitro maturation can offer advantages, such as to avoid the use of large doses gonadotropins and also be an alternative approach to the use of endocrine stimulation to obtain pre-ovulatory oocytes in all cycles. Objective: The objective of the study is to determine the effect of vitrification technique and several biochemical materials on outcomes of in vitro maturation. Materials and Methods: Normal and viable immature oocytes divided into two major groups including: control group and vitrification technique group. Post-thawing, each major group subdivided into four in vitro maturation (IVM) groups using SMART medium with special additives involving: (G1) group: contained gonadotropins (Gn) only, (G2) group: supplemented with Gn and sucrose (4%), (G3) group: consisted of Gn, sucrose (4%) and follicular fluid (FF) (5%), and (G4) group: contained Gn, sucrose (4%) and FF (10%).Then, assessed the results of in vitro maturation. Results: The results of in vitro maturation for control group shows non significant differences (P>0.05) among all groups. While, a significant increase (P<0.05) in percentage of IVM was achieved when compared G3 and G4 groups with G1 and G2 groups in vitrification technique. Therefore, comparison the results of IVM between control group vitrification technique group appeared a significant difference (P<0.05) in G1 groups and also between G2 groups. However, non significant difference (P>0.05) was appeared between G3 groups and also between G4 groups when comparing between control group and vitrification technique group. Conclusions: Vitrification of immature oocytes were appeared as a promise technique for preservation of oocytes. As well as, the addition of follicular fluid (FF) to maturation medium produced the best results for in vitro maturation (IVM).
Background: Unlike sperm production in men which is continuous, women are born with all their eggs and they do not produce any more. Technique to bank eggs would allow girls and women to have the same reproductive options as men when faced with a serious disease and the long term complications of chemotherapies that threatens to destroy their eggs. Objective: The aim of this study is to improve the efficiency of existing ovarian cryopreservation, by following the most recent method named needle immersed vitrification (NIV) beside the slow freezing method. In this review we discussed also the historical description of the methods used, freezing and vitrification of mature and immature oocytes, this include comparison of principles, procedures and results as reported in the literature. Materials and Methods: A total of 285 fragments of human ovarian tissues were isolated and cryopreserved from 36 women aging 26 - 55 years old in the Reproductive Unit, Lubeck-Germany. Ovarian tissue strips of 1-3 mm thick of ovarian cortical biopsies obtained from patients. The collected human ovarian cortex fragments were assigned to two different cryopreservation procedures, slow-freezing and NIV. On the other hand, a total of 80 patients (100 cycles) with polycystic ovaries (PCO) were underwent in vitro maturation (IVM) treatment. The number of inspirated immature oocytes was 536. Vitrification of immature oocytes were carried out. Results: Successful freezing and storing were performed on 285 fragments of ovarian cortex tissue from 36 patients by two cryopreservation protocols as mentioned before but these tissues do not thaw and use yet. Concerning the IVM, the percentage of maturation, fertilization, survival, embryo transfer, and pregnancy rates were 55.2%, 44.5%, 96.2%, 88.1%, and 10.6%, respectively. Conclusion: Recent advances in freezing technology, modifications of conventional protocols used and continuing optimization of vitrification have efficiently improved the method. These results may lead to increase the possibility of preserving fertility by cryopreservation of ovarian tissue. Ovarian tissue banking can offer hope for cancer patients who want to safe guard their fertility against sterilizing chemotherapy and radiotherapy. Immature oocytes can be successfully isolated from the oophorectomy specimen regardless of the day of menstrual cycle, and undergo IVM and cryopreservation.