1
|
Casciani V, Monseur B, Cimadomo D, Alvero R, Rienzi L. Oocyte and embryo cryopreservation in assisted reproductive technology: past achievements and current challenges. Fertil Steril 2023; 120:506-520. [PMID: 37290552 DOI: 10.1016/j.fertnstert.2023.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/27/2023] [Accepted: 06/01/2023] [Indexed: 06/10/2023]
Abstract
Cryopreservation has revolutionized the treatment of infertility and fertility preservation. This review summarizes the milestones that paved the way to the current routinary clinical implementation of this game-changing practice in assisted reproductive technology. Still, evidence to support "the best practice" in cryopreservation is controversial and several protocol adaptations exist that were described and compared here, such as cumulus-intact vs. cumulus-free oocyte cryopreservation, artificial collapse, assisted hatching, closed vs. open carriers, and others. A last matter of concern is whether cryostorage duration may impact oocyte/embryo competence, but the current body of evidence in this regard is reassuring. From social and clinical perspectives, oocyte and embryo cryopreservation has evolved from an afterthought when assisted reproduction was intended for immediate pregnancy with supernumerary embryos of secondary interest to its current purpose, which primarily is to preserve fertility long-term and more comprehensively allow for family planning. However, the initial consenting process, which still is geared to short-term fertility care, may no longer be relevant when the individuals that initially preserved the tissues have completed their reproductive journey. A more encompassing counseling model is required to address changing patient values over time.
Collapse
Affiliation(s)
- Valentina Casciani
- IVIRMA Global Research Alliance, GENERA, Clinica Valle Giulia, Rome, Italy
| | - Brent Monseur
- Stanford Fertility and Reproductive Health, Stanford University, Sunnyvale, California
| | - Danilo Cimadomo
- IVIRMA Global Research Alliance, GENERA, Clinica Valle Giulia, Rome, Italy
| | - Ruben Alvero
- Stanford Fertility and Reproductive Health, Stanford University, Sunnyvale, California
| | - Laura Rienzi
- IVIRMA Global Research Alliance, GENERA, Clinica Valle Giulia, Rome, Italy; Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy.
| |
Collapse
|
2
|
Marschalek J, Hager M, Wanderer S, Ott J, Frank M, Schneeberger C, Pietrowski D. Different Impacts of Cryopreservation in Endothelial and Epithelial Ovarian Cells. Int J Mol Sci 2023; 24:12225. [PMID: 37569601 PMCID: PMC10418832 DOI: 10.3390/ijms241512225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/27/2023] [Accepted: 07/29/2023] [Indexed: 08/13/2023] Open
Abstract
The aim of our laboratory-based study was to investigate the extent of delayed-onset cell death after cryopreservation in endothelial and epithelial cell lines of ovarian origin. We found differences in percentages of vital cells directly after warming and after cultivation for 48 to 72 h. A granulosa cell line of endothelial origin (KGN) and an epithelial cell line (OvCar-3) were used. In both DMSO-containing and DMSO-free protocols, significant differences in vitality rates between the different cell lines when using open and closed vitrification could be shown (DMSO-containing: KGN open vs. OvCar open, p = 0.001; KGN closed vs. OvCar closed, p = 0.001; DMSO-free: KGN open vs. OvCar open, p = 0.001; KGN closed vs. OvCar closed, p = 0.031). Furthermore, there was a marked difference in the percentage of vital cells immediately after warming and after cultivation for 48 to 72 h; whereas the KGN cell line showed a loss of cell viability of 41% using a DMSO-containing protocol, the OvCar-3 cell loss was only 11% after cultivation. Using a DMSO-free protocol, the percentages of late-onset cell death were 77% and 48% for KGN and OvCar-3 cells, respectively. Our data support the hypothesis that cryopreservation-induced damage is cell type and cryoprotective agent dependent.
Collapse
Affiliation(s)
- Julian Marschalek
- Department of Obstetrics and Gynecology, Medical University of Vienna, Spitalgasse 23, 1090 Vienna, Austria; (J.M.); (M.H.); (J.O.); (M.F.); (C.S.)
| | - Marlene Hager
- Department of Obstetrics and Gynecology, Medical University of Vienna, Spitalgasse 23, 1090 Vienna, Austria; (J.M.); (M.H.); (J.O.); (M.F.); (C.S.)
| | - Sophie Wanderer
- FH Campus Wien, University of Applied Science, 1100 Vienna, Austria
| | - Johannes Ott
- Department of Obstetrics and Gynecology, Medical University of Vienna, Spitalgasse 23, 1090 Vienna, Austria; (J.M.); (M.H.); (J.O.); (M.F.); (C.S.)
| | - Maria Frank
- Department of Obstetrics and Gynecology, Medical University of Vienna, Spitalgasse 23, 1090 Vienna, Austria; (J.M.); (M.H.); (J.O.); (M.F.); (C.S.)
| | - Christian Schneeberger
- Department of Obstetrics and Gynecology, Medical University of Vienna, Spitalgasse 23, 1090 Vienna, Austria; (J.M.); (M.H.); (J.O.); (M.F.); (C.S.)
| | - Detlef Pietrowski
- Department of Obstetrics and Gynecology, Medical University of Vienna, Spitalgasse 23, 1090 Vienna, Austria; (J.M.); (M.H.); (J.O.); (M.F.); (C.S.)
| |
Collapse
|
3
|
Angel-Velez D, De Coster T, Azari-Dolatabad N, Fernandez-Montoro A, Benedetti C, Bogado Pascottini O, Woelders H, Van Soom A, Smits K. New Alternative Mixtures of Cryoprotectants for Equine Immature Oocyte Vitrification. Animals (Basel) 2021; 11:ani11113077. [PMID: 34827809 PMCID: PMC8614364 DOI: 10.3390/ani11113077] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Oocyte cryopreservation allows female gametes to be conserved for long periods, which would be of benefit for mares of high genetic merit, but its efficiency is not satisfactory yet. Therefore, the aim of this study was to optimize a vitrification protocol for equine oocytes using a systematic approach. We performed a side-by-side comparison of different cryoprotective agents (CPAs) during the vitrification and warming of equine oocytes. In the first experiment, a fixed mixture of CPAs that enter the oocyte was used, and three sugars were compared, which cannot penetrate the oocyte but provide protection through an osmotic effect. In the second experiment, one sugar from the first experiment was selected to compare three mixtures of CPAs that enter the oocyte. Overall, the embryo development was reduced after oocyte cryopreservation when compared to fresh oocytes. Yet, we were able to produce embryos with all six cryoprotective agent mixtures, and we identified one promising combination of cryoprotectants, consisting of propylene glycol, ethylene glycol, and galactose, that resulted in blastocyst rates in the same range as the fresh control group. Abstract Equine oocyte vitrification would benefit the growing in vitro embryo production programs, but further optimization of the protocol is necessary to reach clinical efficiency. Therefore, we aimed to perform a direct comparison of non-permeating and permeating cryoprotective agents (CPAs) during the vitrification and warming of equine immature oocytes. In the first experiment, cumulus oocytes complexes (COCs) were vitrified comparing sucrose, trehalose, and galactose in combination with ethylene glycol (EG) and dimethyl sulfoxide (DMSO). In the second experiment, the COCs were vitrified using three mixtures of permeating CPAs in a 50:50 volume ratio (ethylene glycol-dimethyl sulfoxide (ED), propylene glycol-ethylene glycol (PE), and propylene glycol-dimethyl sulfoxide (PD)) with galactose and warmed in different galactose concentrations (0.3 or 0.5 mol/L). Overall, all the treatments supported blastocyst formation, but the developmental rates were lower for all the vitrified groups in the first (4.3 to 7.6%) and the second (3.5 to 9.4%) experiment compared to the control (26.5 and 34.2%, respectively; p < 0.01). In the first experiment, the maturation was not affected by vitrification. The sucrose exhibited lower cleavage than the control (p = 0.02). Although the galactose tended to have lower maturation than trehalose (p = 0.060) and control (p = 0.069), the highest numerical cleavage and blastocyst rates were obtained with this CPA. In the second experiment, the maturation, cleavage, and blastocyst rates were similar between the treatments. Compared to the control, only the ED reached similar maturation (p = 0.02) and PE similar cleavage (p = 0.1). The galactose concentration during warming did not affect the maturation, cleavage, or blastocyst rates (p > 0.1), but the PE-0.3 exhibited the highest blastocyst rate (15.1%) among the treatments, being the only one comparable to the control (34.2%). As such, PE–galactose provides a valuable option for equine immature oocyte vitrification and should be considered for the future optimization of the protocol.
Collapse
Affiliation(s)
- Daniel Angel-Velez
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; (T.D.C.); (N.A.-D.); (A.F.-M.); (C.B.); (O.B.P.); (A.V.S.); (K.S.)
- Research Group in Animal Sciences—INCA-CES, Universidad CES, Medellin 050021, Colombia
- Correspondence: or ; Tel.: +32-4-5614-4543
| | - Tine De Coster
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; (T.D.C.); (N.A.-D.); (A.F.-M.); (C.B.); (O.B.P.); (A.V.S.); (K.S.)
| | - Nima Azari-Dolatabad
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; (T.D.C.); (N.A.-D.); (A.F.-M.); (C.B.); (O.B.P.); (A.V.S.); (K.S.)
| | - Andrea Fernandez-Montoro
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; (T.D.C.); (N.A.-D.); (A.F.-M.); (C.B.); (O.B.P.); (A.V.S.); (K.S.)
| | - Camilla Benedetti
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; (T.D.C.); (N.A.-D.); (A.F.-M.); (C.B.); (O.B.P.); (A.V.S.); (K.S.)
| | - Osvaldo Bogado Pascottini
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; (T.D.C.); (N.A.-D.); (A.F.-M.); (C.B.); (O.B.P.); (A.V.S.); (K.S.)
- Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Henri Woelders
- Wageningen Livestock Research, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands;
| | - Ann Van Soom
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; (T.D.C.); (N.A.-D.); (A.F.-M.); (C.B.); (O.B.P.); (A.V.S.); (K.S.)
| | - Katrien Smits
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; (T.D.C.); (N.A.-D.); (A.F.-M.); (C.B.); (O.B.P.); (A.V.S.); (K.S.)
| |
Collapse
|
4
|
Park JK, Lee JH, Park EA, Lim HJ, Lyu SW, Lee WS, Kim J, Song H. Development of Optimized Vitrification Procedures Using Closed Carrier System to Improve the Survival and Developmental Competence of Vitrified Mouse Oocytes. Cells 2021; 10:cells10071670. [PMID: 34359838 PMCID: PMC8304188 DOI: 10.3390/cells10071670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 06/28/2021] [Accepted: 06/28/2021] [Indexed: 11/16/2022] Open
Abstract
The open carrier system (OC) is used for vitrification due to its high efficiency in preserving female fertility, but concerns remain that it bears possible risks of cross-contamination. Closed carrier systems (CC) could be an alternative to the OC to increase safety. However, the viability and developmental competence of vitrified/warmed (VW) oocytes using the CC were significantly lower than with OC. We aimed to improve the efficiency of the CC. Metaphase II oocytes were collected from mice after superovulation and subjected to in vitro fertilization after vitrification/warming. Increasing the cooling/warming rate and exposure time to cryoprotectants as key parameters for the CC effectively improved the survival rate and developmental competence of VW oocytes. When all the conditions that improved the outcomes were applied to the conventional CC, hereafter named the modified vitrification/warming procedure using CC (mVW-CC), the viability and developmental competence of VW oocytes were significantly improved as compared to those of VW oocytes in the CC. Furthermore, mVW-CC increased the spindle normality of VW oocytes, as well as the cell number of blastocysts developed from VW oocytes. Collectively, our mVW-CC optimized for mouse oocytes can be utilized for humans without concerns regarding possible cross-contamination during vitrification in the future.
Collapse
Affiliation(s)
- Jae Kyun Park
- Department of Biomedical Sciences, CHA University, Seongnam 13488, Korea; (J.K.P.); (J.H.L.)
- CHA Fertility Center Gangnam, CHA University, Seoul 06125, Korea; (S.W.L.); (W.S.L.)
| | - Ju Hee Lee
- Department of Biomedical Sciences, CHA University, Seongnam 13488, Korea; (J.K.P.); (J.H.L.)
| | - Eun A Park
- CHA Fertility Center Seoul Station, CHA University, Seoul 04637, Korea;
| | - Hyunjung J. Lim
- Department of Veterinary Medicine, School of Veterinary Medicine, Konkuk University, Seoul 05029, Korea;
| | - Sang Woo Lyu
- CHA Fertility Center Gangnam, CHA University, Seoul 06125, Korea; (S.W.L.); (W.S.L.)
| | - Woo Sik Lee
- CHA Fertility Center Gangnam, CHA University, Seoul 06125, Korea; (S.W.L.); (W.S.L.)
| | - Jayeon Kim
- CHA Fertility Center Seoul Station, CHA University, Seoul 04637, Korea;
- Correspondence: (J.K.); (H.S.)
| | - Haengseok Song
- Department of Biomedical Sciences, CHA University, Seongnam 13488, Korea; (J.K.P.); (J.H.L.)
- Correspondence: (J.K.); (H.S.)
| |
Collapse
|
5
|
Pietrowski D, Mladek R, Frank M, Erber J, Marschalek J, Schneeberger C. Analyses of human granulosa cell vitality by fluorescence activated cell sorting after rapid cooling. HUM FERTIL 2020; 25:478-486. [PMID: 32914641 DOI: 10.1080/14647273.2020.1817578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In reproductive medicine, the technique of rapid cooling becomes increasingly important for the preservation of tissue and cells. In order to protect the cells, incubation in different cryopreservation solutions is essential. The speed of the cooling process also makes a pivotal contribution to the success of this method. Using Flourescence Activated Cell Sorting (FACS), we investigated the impact of an open rapid and a closed rapid cooling technique on the vitality of human granulosa cells. Furthermore, we examined effects of the different solutions used for rapid cooling and warming before and after rapid cooling. We found a significant lower proportion of vital cells after rapid cooling compared to untreated controls independently of the technique and the tube size. However, we did not find any significant differences between open and closed rapid cooling. In both, a lower proportion of vital granulosa cells were found after incubation in rapid cooling solution only compared to warming solution only. Our results lend support to the conclusion that the difference of cooling-speed between open and closed rapid cooling is, in our settings, not crucial for the success of the procedure and that cryoprotective agents in the rapid cooling solutions have a higher potential to cause severe cell damage than agents used for warming.
Collapse
Affiliation(s)
- Detlef Pietrowski
- Department of Obstetrics and Gynecology, Medical University Vienna, Vienna, Austria
| | - Raphaela Mladek
- FH Campus Wien, University of Applied Science, Vienna, Austria
| | - Maria Frank
- Department of Obstetrics and Gynecology, Medical University Vienna, Vienna, Austria
| | - Julia Erber
- Faculty of Life Science, University of Vienna, Vienna, Austria
| | - Julian Marschalek
- Department of Obstetrics and Gynecology, Medical University Vienna, Vienna, Austria
| | | |
Collapse
|
6
|
Abstract
Invited talks of old scientists are standard parts of international meetings, just like opening ceremonies, selection of committees and cocktail parties. Typically, senior scientists and emeritus professors prepare seemingly important and scientifically correct lectures about the great pioneers and past achievements of a given discipline. In fact, these speeches are usually meaningless and extremely boring. Kind of polite acknowledgments of the past contribution of the old guy who is already unable to provide any news to the audience. Farewells, just before the obituary. I am not sure I can make it more interesting, but at least give it a try by focusing on negative events: controversies, fiascos, and absurdities that have hampered the advancement - some of them up till today. I will make efforts to be sincere and sharp; I apologize for the biased and close to sarcastic tone in some statements. I will also talk a lot about the human field, as the two areas are strongly related, and in fact, the in vivo experiences and achievements in humans vastly surpass those in domestic species in most countries. I will not go back to historical ages, just start with my personal experiences since 1990, although it may still seem to be medieval for most of the audience.
Collapse
Affiliation(s)
- Gábor Vajta
- RVT Australia, Cairns, Australia; VitaVitro Pty., Ltd, Shenzhen, China.
| |
Collapse
|
7
|
Closed vitrification system and egg donation: Predictive factors of oocyte survival and pregnancy. J Gynecol Obstet Hum Reprod 2020; 49:101687. [PMID: 31953194 DOI: 10.1016/j.jogoh.2020.101687] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 11/23/2022]
Abstract
Although many studies have demonstrated the superiority of ultra-fast freezing compared with slow freezing, the debate is still ongoing concerning the best type of vitrification method: direct exposure to liquid nitrogen (i.e., open systems), or sterile system without contact with liquid nitrogen (i.e., closed systems). The aims of this study were to share our experience on closed vitrification systems in the framework of our egg donation programme with fully asynchronous cycles, and to identify predictive factors of successful outcome in this context. Logistic regression analysis indicated that the number of vitrified oocytes was the only factor predictive of the oocyte survival rate and of clinical pregnancy. The addition of one vitrified oocyte increased by 15 % the odds of oocyte survival. When the oocyte survival rate was considered as a continuous variable, the following results were obtained: 7 % of clinical pregnancy probability for 50 % survival rate, 15 % for 75 % survival rate, and 32 % for 100 % survival rate. The rates of oocyte survival and fertilization, embryo implantation, and clinical pregnancy were in agreement with the recommended values established by ALPHA Scientists in Reproductive Medicine in 2012. On the basis of these results, and according to the European directives on safety, we validate the routine use of closed oocyte vitrification systems for egg donation programmes. These results must be confirmed in larger samples before extrapolation to all patient types.
Collapse
|
8
|
Mintziori G, Veneti S, Kolibianakis EM, Grimbizis GF, Goulis DG. Egg freezing and late motherhood. Maturitas 2019; 125:1-4. [PMID: 31133209 DOI: 10.1016/j.maturitas.2019.03.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/18/2019] [Accepted: 03/24/2019] [Indexed: 02/07/2023]
Abstract
Egg freezing was initially used as an intervention for iatrogenic ovarian insufficiency. Nowadays, it is not considered an experimental procedure, and it is increasingly popular among healthy women who wish to maintain their reproductive potential (fertility preservation). This review summarises the evidence on egg freezing technology, reproductive outcomes and long-term effects, as well as its psychological and socioeconomic implications. Egg freezing technology is advancing, with vitrification being the current method of choice, due to its effectiveness. The reproductive outcomes following egg freezing appear to be promising, though the strong negative association with maternal age has to be taken into consideration. Unfortunately, data on long-term outcomes are missing, raising safety issues. Egg freezing has several socioeconomic implications involving health risks, as well as financial and psychological factors.
Collapse
Affiliation(s)
- Gesthimani Mintziori
- Unit of Reproductive Endocrinology, 1st Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece. gefsi.@auth.gr
| | - Stavroula Veneti
- Unit of Reproductive Endocrinology, 1st Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Efstratios M Kolibianakis
- Unit of Human Reproduction, 1st Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Grigorios F Grimbizis
- 1st Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Dimitrios G Goulis
- Unit of Reproductive Endocrinology, 1st Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| |
Collapse
|
9
|
Cai H, Niringiyumukiza JD, Li Y, Lai Q, Jia Y, Su P, Xiang W. Open versus closed vitrification system of human oocytes and embryos: a systematic review and meta-analysis of embryologic and clinical outcomes. Reprod Biol Endocrinol 2018; 16:123. [PMID: 30522492 PMCID: PMC6284284 DOI: 10.1186/s12958-018-0440-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 11/19/2018] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The objective of this study was to carry out a systematic review and meta-analysis of embryologic and clinical outcomes following open versus closed vitrification of human oocytes and embryos. METHODS An electronic literature search was conducted in main electronic databases up to June 30, 2018 using the following key terms: 'oocyte', 'embryo', 'blastocyst', 'vitrification', 'cryopreservation', 'device', 'survival rate', 'pregnancy rate', etc. A meta-analysis was performed using a random effect model to estimate the value of risk ratios (RRs) and 95% confidence interval (CI). Subgroup analyses and sensitivity analyses were carried out to further confirm the results. RESULTS Twelve (Eight prospective and four retrospective) studies comparing open versus closed vitrification of human oocytes or embryos were included. For prospective studies on oocytes, no evidence for a significant difference in cryosurvival rate (RR = 0.91, 95% CI: 0.80-1.03, P = 0.14; n = 2048) or clinical pregnancy rate (RR = 1.29, 95% CI: 0.80-2.06, P = 0.30; n = 150) was observed. Additionally, there were no significant differences between the two methods concerning secondary endpoints included positive βHCG rate, implantation rate, miscarriage rate, ongoing pregnancy rate, live birth rate, cancellation rate, babies born per transferred blastocysts, or multiple birth rate (P > 0.05). The results of the retrospective studies were similar as the prospective studies. CONCLUSIONS It is still impossible to conclude that closed vitrification system could be a substitution for open system in human oocyte and embryo cryopreservation based on current evidence. Therefore, more well-designed prospective studies addressing these issues are still warranted.
Collapse
Affiliation(s)
- Hongcai Cai
- Family Planning Research Institute/Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Jean Damascene Niringiyumukiza
- Family Planning Research Institute/Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Yamin Li
- Family Planning Research Institute/Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Qiaohong Lai
- Center of Reproductive Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Yinzhao Jia
- Department of General Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Ping Su
- Family Planning Research Institute/Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
| | - Wenpei Xiang
- Family Planning Research Institute/Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
| |
Collapse
|