Background: Oocyte vitrification is a promising technique. The choice of appropriate types and concentrations of cryoprotectants is essential for the success of the oocytes vitrification. Objective: This study aimed to investigate the effect of vitrification on viability and morphology of oocytes and to compare the effect of several cryoprotectants on the viability and morphology of oocytes during vitrification and post-thawing. Methods: The sheep ovaries were collected from the local abattoir. Only normal and viable oocytes were included in this study. By using cryotop, immature oocytes that were viable with normal morphology were vitrified with 15% DMSO and 15% EG supplemented with 0.0 M, 0.25M, or 0.5 M of either sucrose or trehalose as control and treated groups. Oocytes viability and morphology were assessed post-aspiration and post-thawing. Results: Fromthe results of the present study, the percentage of post-thawing normal and viable oocyte reported with the use of 0.5M trehalose and EG in vitrification solution (VS) significantly)P<0.05) higher than the percentage of post-thawing normal and viable oocyte reported with use of 0.25 M trehalose and EG. Conclusion: Vitrification is simple technique and easy to perform but it needs some experience to prevent any oocyte loss during vitrification and thawing processing. The use of 0.5 M of either sucrose or trehalose in vitrification solution improves the percentage of post-thawing viable and normal oocytes.
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.
Background: it is important to study a history of the science to appreciate the past as a motive for hard work in the present for better future. In the other hand, the factors affecting pregnancy rate of frozen embryos are yet to be clarified at different embryonic developmental stages. Objectives: to record a brief history of embryo cryopreservation in Iraq and to study many clinical and embryological factors that might affect the pregnancy rate. Subjects, materials and Method: a cross-sectional study of many clinical and em-bryological variable, where120 frozen-thawed embryo transfer cycles enrolled in the study at the period from January 2017 till July 2018. The variables were sta-tistically analyzed first by one factor analysis comparing between pregnant and non-pregnant cases; then by multivariate logistic regression analysis to illustrate main factors without a possible confounder effect. Results: In one factor analysis, the following variables showed a significantly high effect on pregnancy rate (P value <0.001) which are women’s age, women’s weight, number of retrieved oocytes, mature oocytes and good quality embryos, developmental stage, E2 level, and endometrial thickness. While in multivariate logistic regression analysis the women’s weight, the number of retrieved oocytes and good quality embryos were the main factors. Conclusions: it is judiciously to consider these factors while managing infertile couples with embryo cryopreservation programs especially the modifiable fac-tors.