Estudio exploratorio de las motivaciones para la criopreservación de ovocitos en forma electiva / An exploratory study of motivations for elective oocyte cryopreservation

Introducción La vitrificación de óvulos es un avance científico que ha cambiado la perspectiva reproductiva de la sociedad humana. Este procedimiento se ha ofrecido como alternativa a la postergación voluntaria del embarazo, confiriéndole a la mujer una nueva perspectiva en su autonomía reproductiva. El número de mujeres que consultan y luego optan por congelar ovocitos ha aumentado en forma casi exponencial en Chile y en todo el mundo. En nuestro país, hay poco conocimiento acerca de la motivación, experiencia y resultados de la criopreservación electiva de ovocitos en Chile. El objetivo fue conocer la motivación, experiencia y el deseo reproductivo futuro de este grupo de mujeres sometidas a esta técnica. Métodos Estudio descriptivo transversal, basado en un cuestionario enviado por correo electrónico en el que participaron mujeres que se habían sometido previamente a criopreservación electiva de ovocitos entre enero de 2011 y diciembre de 2019 en Clínica Alemana, Santiago de Chile. Resultados De 342 mujeres que habían completado un ciclo de criopreservación electiva de ovocitos, 193 aceptaron participar y de estas, 98 (51%) de las mujeres contestaron la encuesta en forma satisfactoria. Se establecieron criterios de exclusión a aquellas mujeres que se habían sometido a este procedimiento por indicación médica como la endometriosis, el cáncer y la baja reserva ovárica. El motivo más frecuente para realizarse el procedimiento fue la edad (44%). En relación al procedimiento; el 94% no se arrepiente de haberlo realizado y 74% de las mujeres cree que utilizará sus ovocitos en algún momento de su vida. Por último, desde que se realizaron la criopreservación de ovocitos a la fecha, el 11% de las mujeres encuestadas ha usado sus ovocitos vitrificados y 27% ha logrado embarazarse con estos. Conclusión Las mujeres que se someten a criopreservación electiva de ovocitos por razones sociales, son principalmente mujeres sin pareja que tiene como motivación principal su edad reproductiva y la gran mayoría de ellas no se arrepienten de haberlo realizado.

Introduction Oocyte vitrification is a scientific advance that has changed the reproductive perspective of human society. This procedure has been offered as an alternative to the voluntary postponement of pregnancy, giving women a new perspective on their reproductive autonomy. The number of women who consult and then choose to freeze oocytes has increased almost exponentially in Chile and throughout the world. There is little knowledge about the motivation, experience, and results of elective oocyte cryopreservation in Chile. The objective was to know the motivation, experience, and future reproductive desire of the women who underwent this technique. Methods Cross-sectional descriptive study based on a questionnaire sent by e-mail in which females who had previously undergone elective oocyte cryopreservation between January 2011 and December 2019 at Clínica Alemana, Santiago, Chile, participated. Results Of 342 women who had completed a cycle of elective oocyte cryopreservation, 193 agreed to participate, and of these, 98 (51%) answered the survey satisfactorily. Women who underwent this procedure for medical indication, including endometriosis, cancer, and low ovarian reserve, were excluded. The most frequent reason for the procedure was age (44%). Concerning the procedure: 94% do not regret having it done, and 74% of the women believe that they will use their oocytes at some point in their lives. Finally, from the time of oocyte cryopreservation to date, 11% of the surveyed women have used their vitrified oocytes, and 27% have become pregnant. Conclusions Women who undergo elective oocyte cryopreservation for social reasons are mainly women without a partner whose main motivation is their reproductive age. The vast majority do not regret doing so.

Use of melatonin as an inhibitor of apoptotic process for cryopreservation of zebrafish (Danio rerio) embryos / Uso da melatonina como inibidor do processo apoptotico para a criopreservação de embriões de zebrafish (Danio rerio)

This study investigated the use of melatonin to arrest the effects of apoptosis in vitrified zebrafish (D. rerio) embryos. Dechorionated embryos at 22-24 somite-stage were divided (n = 60/treatment) into a non-vitrified (Control Group, 0 M melatonin) and vitrified treatments with 0 M (T1), 1 µM (T2) and 1 mM of melatonin (T3). For vitrified treatments, a solution methanol/propylene glycol based was used and the embryos stored in -196 °C for a week. After thaw, survival rate, scanning electron microscopy, expression of anti (bcl-2) and pro-apoptotic (bax/caspase-3) genes, reactive oxygen species (ROS) formation and DNA fragmentation analyses were performed. No live embryos were obtained from vitrified treatments, observing a rapid degeneration immediately after thawing, with the vitelline layer rupture and leakage of its content, followed by breakdown of epithelial cells and melanisation of the tissue. Regarding the apoptotic process, T3 had the highest relative gene expression, for the three genes (P < 0.05) furthermore, T2 had similar expression of pro-apoptotic genes to CG (P < 0.05). ROS formation revealed that CG presented lower percentage of embryo surface area affected (3.80 ± 0.40%) (P < 0.05), in contrast, no differences were found among the other groups. T1 was most significantly (P < 0.05) damaged by DNA fragmentation. The vitrified groups with melatonin had similar damage levels of CG (P > 0.05). The inclusion of 1 µM of melatonin in the vitrifying solution, countered the effects of apoptotic process in post-thaw embryos, suggesting its utility in cryopreserving fish embryos.

Este estudo investigou o uso da melatonina para conter os efeitos da apoptose em embriões vitrificados de zebrafish (D. rerio). Embriões descorionados no estágio de 22-24 somitos foram divididos (n = 60 / tratamento) em tratamento não vitrificado (Grupo Controle, melatonina 0 M) e tratamentos vitrificados com 0 M (T1), 1 µM (T2) e 1 mM de melatonina (T3). Para os tratamentos vitrificados, utilizou-se uma solução à base de metanol/propilenoglicol e os embriões foram armazenados em -196 °C por uma semana. Após o descongelamento, foram realizadas análises de taxa de sobrevivência, microscopia eletrônica de varredura, expressão dos genes anti (bcl-2) e pró-apoptóticos (bax/caspase-3), formação de espécies reativas de oxigênio (EROS) e análises de fragmentação de DNA. Não foram obtidos embriões vivos a partir dos tratamentos vitrificados, observando uma rápida degeneração imediatamente após o descongelamento, com ruptura da camada vitelina e vazamento de seu conteúdo, seguida de quebra das células epiteliais e melanização do tecido. Em relação ao processo apoptótico. T3 apresentou expressão gênica relativa alta para os três genes (P <0,05), além disso, T2 apresentou expressão semelhante as dos genes pró-apoptóticos de GC (P <0,05). A formação de EROS revelou que GC apresentou menor percentual de área de superfície embrionária afetada (3,80 ± 0,40%) (P <0,05), ao contrário, não foram encontradas diferenças entre os outros grupos. T1 foi mais significativamente (P <0,05) danificado pela fragmentação do DNA. Os grupos vitrificados com melatonina apresentaram níveis de dano semelhantes ao do GC (P> 0,05). A inclusão de 1 µM de melatonina na solução de vitrificação, contrariou os efeitos do processo apoptótico em embriões pós-descongelamento, sugerindo sua utilidade na criopreservação de embriões de peixes.

Use of melatonin as an inhibitor of apoptotic process for cryopreservation of zebrafish (Danio rerio) embryos / Uso da melatonina como inibidor do processo apoptotico para a criopreservação de embriões de zebrafish (Danio rerio)

This study investigated the use of melatonin to arrest the effects of apoptosis in vitrified zebrafish (D. rerio) embryos. Dechorionated embryos at 22-24 somite-stage were divided (n = 60/treatment) into a non-vitrified (Control Group, 0 M melatonin) and vitrified treatments with 0 M (T1), 1 µM (T2) and 1 mM of melatonin (T3). For vitrified treatments, a solution methanol/propylene glycol based was used and the embryos stored in -196 °C for a week. After thaw, survival rate, scanning electron microscopy, expression of anti (bcl-2) and pro-apoptotic (bax/caspase-3) genes, reactive oxygen species (ROS) formation and DNA fragmentation analyses were performed. No live embryos were obtained from vitrified treatments, observing a rapid degeneration immediately after thawing, with the vitelline layer rupture and leakage of its content, followed by breakdown of epithelial cells and melanisation of the tissue. Regarding the apoptotic process, T3 had the highest relative gene expression, for the three genes (P 0.05). The inclusion of 1 µM of melatonin in the vitrifying solution, countered the effects of apoptotic process in post-thaw embryos, suggesting its utility in cryopreserving fish embryos.

Este estudo investigou o uso da melatonina para conter os efeitos da apoptose em embriões vitrificados de zebrafish (D. rerio). Embriões descorionados no estágio de 22-24 somitos foram divididos (n = 60 / tratamento) em tratamento não vitrificado (Grupo Controle, melatonina 0 M) e tratamentos vitrificados com 0 M (T1), 1 µM (T2) e 1 mM de melatonina (T3). Para os tratamentos vitrificados, utilizou-se uma solução à base de metanol/propilenoglicol e os embriões foram armazenados em -196 °C por uma semana. Após o descongelamento, foram realizadas análises de taxa de sobrevivência, microscopia eletrônica de varredura, expressão dos genes anti (bcl-2) e pró-apoptóticos (bax/caspase-3), formação de espécies reativas de oxigênio (EROS) e análises de fragmentação de DNA. Não foram obtidos embriões vivos a partir dos tratamentos vitrificados, observando uma rápida degeneração imediatamente após o descongelamento, com ruptura da camada vitelina e vazamento de seu conteúdo, seguida de quebra das células epiteliais e melanização do tecido. Em relação ao processo apoptótico. T3 apresentou expressão gênica relativa alta para os três genes (P 0,05). A inclusão de 1 µM de melatonina na solução de vitrificação, contrariou os efeitos do processo apoptótico em embriões pós-descongelamento, sugerindo sua utilidade na criopreservação de embriões de peixes.

Use of melatonin as an inhibitor of apoptotic process for cryopreservation of zebrafish (Danio rerio) embryos

Abstract This study investigated the use of melatonin to arrest the effects of apoptosis in vitrified zebrafish (D. rerio) embryos. Dechorionated embryos at 22-24 somite-stage were divided (n = 60/treatment) into a non-vitrified (Control Group, 0 M melatonin) and vitrified treatments with 0 M (T1), 1 µM (T2) and 1 mM of melatonin (T3). For vitrified treatments, a solution methanol/propylene glycol based was used and the embryos stored in -196 °C for a week. After thaw, survival rate, scanning electron microscopy, expression of anti (bcl-2) and pro-apoptotic (bax/caspase-3) genes, reactive oxygen species (ROS) formation and DNA fragmentation analyses were performed. No live embryos were obtained from vitrified treatments, observing a rapid degeneration immediately after thawing, with the vitelline layer rupture and leakage of its content, followed by breakdown of epithelial cells and melanisation of the tissue. Regarding the apoptotic process, T3 had the highest relative gene expression, for the three genes (P 0.05) furthermore, T2 had similar expression of pro-apoptotic genes to CG (P 0.05). ROS formation revealed that CG presented lower percentage of embryo surface area affected (3.80 ± 0.40%) (P 0.05), in contrast, no differences were found among the other groups. T1 was most significantly (P 0.05) damaged by DNA fragmentation. The vitrified groups with melatonin had similar damage levels of CG (P > 0.05). The inclusion of 1 µM of melatonin in the vitrifying solution, countered the effects of apoptotic process in post-thaw embryos, suggesting its utility in cryopreserving fish embryos.

Resumo Este estudo investigou o uso da melatonina para conter os efeitos da apoptose em embriões vitrificados de zebrafish (D. rerio). Embriões descorionados no estágio de 22-24 somitos foram divididos (n = 60 / tratamento) em tratamento não vitrificado (Grupo Controle, melatonina 0 M) e tratamentos vitrificados com 0 M (T1), 1 µM (T2) e 1 mM de melatonina (T3). Para os tratamentos vitrificados, utilizou-se uma solução à base de metanol/propilenoglicol e os embriões foram armazenados em -196 °C por uma semana. Após o descongelamento, foram realizadas análises de taxa de sobrevivência, microscopia eletrônica de varredura, expressão dos genes anti (bcl-2) e pró-apoptóticos (bax/caspase-3), formação de espécies reativas de oxigênio (EROS) e análises de fragmentação de DNA. Não foram obtidos embriões vivos a partir dos tratamentos vitrificados, observando uma rápida degeneração imediatamente após o descongelamento, com ruptura da camada vitelina e vazamento de seu conteúdo, seguida de quebra das células epiteliais e melanização do tecido. Em relação ao processo apoptótico. T3 apresentou expressão gênica relativa alta para os três genes (P 0,05), além disso, T2 apresentou expressão semelhante as dos genes pró-apoptóticos de GC (P 0,05). A formação de EROS revelou que GC apresentou menor percentual de área de superfície embrionária afetada (3,80 ± 0,40%) (P 0,05), ao contrário, não foram encontradas diferenças entre os outros grupos. T1 foi mais significativamente (P 0,05) danificado pela fragmentação do DNA. Os grupos vitrificados com melatonina apresentaram níveis de dano semelhantes ao do GC (P> 0,05). A inclusão de 1 µM de melatonina na solução de vitrificação, contrariou os efeitos do processo apoptótico em embriões pós-descongelamento, sugerindo sua utilidade na criopreservação de embriões de peixes.

Ex vivo retrieval of mature oocytes for fertility preservation in a patient with bilateral borderline ovarian tumor / Recuperação ex vivo de oócitos maduros para preservação da fertilidade em paciente com tumor ovariano borderline bilateral

Abstract We report a case of ultrasound-guided ex vivo oocyte retrieval for fertility preservation in a woman with bilateral borderline ovarian tumor, for whom conventional transvaginal oocyte retrieval was deemed unsafe because of the increased risk of malignant cell spillage. Ovarian stimulation with gonadotropins was performed. Surgery was scheduled according to the ovarian response to exogenous gonadotropic stimulation; oophorectomized specimens were obtained by laparoscopy, and oocyte retrieval was performed ~ 37 hours after the ovulatory trigger. The sum of 20 ovarian follicles were aspirated, and 16 oocytes were obtained.We performed vitrification of 12 metaphase II oocytes and 3 oocytes matured in vitro. Our result emphasizes the viability of ex vivo mature oocyte retrieval after controlled ovarian stimulation for those with high risk of malignant dissemination by conventional approach.

Resumo Relatamos um caso de obtenção ex vivo de óvulos, guiada por ultrassonografia, para preservação da fertilidade em uma mulher com tumor ovariano borderline bilateral, para quem a recuperação transvaginal convencional foi considerada insegura, devido ao aumento do risco de disseminação de célulasmalignas. Foi realizada estimulação ovariana com gonadotrofinas. A cirurgia foi agendada de acordo com a resposta ovariana à estimulação gonadotrófica exógena; após ooforectomia por laparoscopia, ~ 37 horas após a maturação folicular, procedeu-se à recuperação extracorpórea de oócitos. Umtotal de 20 folículos ovarianos foi aspirado e 16 complexos cumulus foramobtidos, resultando na vitrificação de 12 oócitos maduros e de 3 oócitos imaturos amadurecidos in vitro. Nosso resultado enfatiza a viabilidade da recuperação ex vivo de oócitos maduros após estimulação ovariana controlada para mulheres com alto risco de disseminação maligna pela captação oocitária realizada convencionalmente pela via transvaginal.

Freeze-all policy for in vitro fertilization in women with normal response to ovarian stimulation / Congelamento de todos os embriões em ciclos de fertilização in vitro em mulheres com resposta normal à estimulação ovariana

ABSTRACT Objective To answer the question if the freeze-all strategy and subsequent frozen embryo transfer is preferable to fresh embryo transfer for patients with normal response to ovarian stimulation (4 to 15 oocytes recovered) during in vitro fertilization treatments. Methods A retrospective cohort from two human reproduction centers between 2013 and 2017. A total of 471 frozen embryo transfers from freeze-all cycles, and 3,208 fresh transfers were included. Results After propensity score matching adjustment for age and number of eggs, 467 freeze-all cycles and 934 fresh cycles were analyzed, revealing no statistically significant difference between groups in relation to clinical pregnancy rate (32.5% in the Freeze-all Group and 32.3% in the Fresh Group, p=0.936). For women aged 40 years and older, we observed a statistically significant higher clinical pregnancy rate when freeze-all strategy was used (29.3% in the Freeze-all Group and 19.8% in the Fresh Group, p=0.04). Conclusion Freeze-all strategy was not superior to fresh transfer for all patients with normal response to ovarian stimulation. However, women aged 40 years and older could benefit from this strategy. This deserves further investigation in future research, preferable in a prospective randomized study.

RESUMO Objetivo Responder à pergunta se a estratégia freeze-all (congelamento de todos os embriões) e subsequente transferência de embriões congelados é preferível à transferência de embriões a fresco em pacientes com resposta normal à estimulação ovariana (4 a 15 ovócitos coletados) durante tratamentos de fertilização in vitro . Métodos Coorte retrospectiva de dois centros de reprodução humana entre 2013 e 2017. No total, foram incluídas 471 transferências de ciclos com congelamento de todos os embriões, e 3.208 transferências a fresco. Resultados Após o ajuste do escore de propensão para idade e número de óvulos, foram analisados 467 ciclos com congelamento de todos os embriões e 934 ciclos a fresco, não havendo diferença estatisticamente significativa entre os grupos em relação à taxa de gravidez clínica (32,5% no Grupo Freeze-all e 32,3% no Grupo a Fresco, p=0,936). Para mulheres com 40 anos ou mais, observamos uma taxa de gravidez clínica estatisticamente maior quando foi utilizada a estratégia freeze-all (29,3% no Grupo Freeze-all e 19,8% no Grupo a Fresco, p=0,04). Conclusão A estratégia freeze-all não foi superior à transferência a fresco para todas as pacientes com resposta normal à estimulação ovariana. No entanto, mulheres com 40 anos ou mais podem ter algum benefício com essa estratégia. Isso justifica uma investigação mais aprofundada em pesquisas futuras e, de preferência, em estudos prospectivos randomizados.

Research progress of methods to promote the survival of cryopreserved ovarian tissue auto-transplantation / 器官移植

With the technology development of cancer treatment, the survival rate of patients with cancer has been significantly improved. However, chemotherapy and radiation therapy may lead to premature ovarian failure and infertility in young women with cancer. Cryopreserved ovarian tissue auto-transplantation is an effective method to preserve fertility of such female patients. At present, the biggest challenge of this technique is mass loss of follicles after transplantation. In this article, the influencing factors and improvement methods of survival of cryopreserved ovarian tissue auto-transplantation were reviewed.

Effects of Magnetic Rewarming on Mechanical Properties of Vitrified Umbilical Artery / 医用生物力学

Objective To study the effect of magnetic rewarming on the morphology and biomechanical properties of vitrified umbilical artery. Methods The vitrified umbilical artery was rewarmed by magnetothermal method and traditional water bath. The temperature distribution and stress in the solution system were analyzed, and the rewarming effect was evaluated by tissue staining and mechanical test. Results Compared with water bath rewarming, the temperature gradient and thermal stress generated by magnetic rewarming were smaller, which could effectively reduce the thermal stress damage during the rewarming stage and achieve rapid and uniform rewarming. Magnetic rewarming could effectively avoid umbilical artery fractures and micro-cracks. After rewarming, the extracellular matrix, collagen fibers, elastic fibers and muscle fibers of the umbilical artery were evenly distributed, which preserved the macro and micro structures of the umbilical artery. The umbilical artery showed different degrees of hardening after water bath and magnetic rewarming, but the elastic modulus and limit stress of the latter were not significantly different from those of fresh umbilical artery, and the latter had unidirectional stretching characteristics similar to that of fresh umbilical artery, showing good elasticity and toughness. Conclusions Compared with water bath rewarming, magnetothermal method can effectively reduce the damage of rewarming stage, ensure the macroscopic, microscopic structure integrity of umbilical artery and better biomechanical properties. The research findings provide important references for cryopreservation of large tissues or organs such as umbilical artery.

Improving native human sperm freezing protection by using a modified vitrification method / 亚洲男科学杂志(英文版)

Slow freezing is the most commonly used technique for the cryopreservation of spermatozoa in clinical practice. However, it has been shown to have a negative impact on sperm function and structure. Vitrification as a successful alternative method has been proved to have better protective effects on human embryos, but vitrification of spermatozoa is still subject to low recovery rates. In this study, a modified vitrification method for native spermatozoa was developed. A total of 28 semen samples were included; each sample was divided into three equal parts and assigned to fresh, slow freezing, and vitrification groups. Sperm vitality, motility, morphology, DNA integrity, and acrosome reaction were assessed for each of the groups. The results showed that vitrification achieves better results for several sperm protection parameters than slow freezing; vitrification achieves a higher recovery rate (P < 0.05), motility (P <0.05), morphology (P <0.05), and curve line velocity (P <0.05) than slow freezing. Furthermore, DNA fragmentation was decreased (P <0.05) and better acrosome protection (P <0.05) was exhibited in the spermatozoa after vitrification. Principal component analysis of all sperm parameters revealed that the vitrification cluster was closer to the fresh cluster, indicating that spermatozoa are better preserved through vitrification. In conclusion, while both slow freezing and vitrification have negative effects on sperm function and structure, the vitrification protocol described here had a relatively better recovery rate (65.8%) and showed improved preservation of several sperm quality parameters compared with slow freezing.

Effects of vitrification and cryostorage duration on single-cell RNA-Seq profiling of vitrified-thawed human metaphase II oocytes / 医学前沿

Oocyte cryopreservation is widely used for clinical and social reasons. Previous studies have demonstrated that conventional slow-freezing cryopreservation procedures, but not storage time, can alter the gene expression profiles of frozen oocytes. Whether vitrification procedures and the related frozen storage durations have any effects on the transcriptomes of human metaphase II oocytes remain unknown. Four women (30-32 years old) who had undergone IVF treatment were recruited for this study. RNA-Seq profiles of 3 fresh oocytes and 13 surviving vitrified-thawed oocytes (3, 3, 4, and 3 oocytes were cryostored for 1,2, 3, and 12 months) were analyzed at a single-cell resolution. A total of 1987 genes were differentially expressed in the 13 vitrified-thawed oocytes. However, no differentially expressed genes were found between any two groups among the 1-, 2-, 3-, and 12-month storage groups. Further analysis revealed that the aberrant genes in the vitrified oocytes were closely related to oogenesis and development. Our findings indicated that the effects of vitrification on the transcriptomes of mature human oocytes are induced by the procedure itself, suggesting that long-term cryostorage of human oocytes is safe.

Effects of Vitrification with Self-made Carriers and Slow Programmed Freezing on Ovarian Tissue of Sheep / 中国医学科学院学报

Objective To investigate the effects of self-made carriers on the cryopreservation of ovarian tissue of sheep. Methods Thirty-two ovaries were randomly assigned to fresh group,programmed freezing group,self-made carrier I vitrification group,and self-made carrier Ⅱ vitrification group.The morphology,proliferation,apoptosis,and estrogen level of the ovarian tissue in each group were observed. Results After cryopreservation,the morphology normal rate of the primordial follicles in programmed freezing group,self-made carrier I vitrification group,and self-made carrier Ⅱ vitrification group were 74.2%,72.8%,and 72.3%,respectively,lower than that(83.7%)in the fresh group(χ

Avaliação da técnica de vitrificação de ovários de camundongos da linhagem B6D2F1, pertencentes ao Instituto de Ciência e Tecnologia em Biomodelos - ICTB/Fiocruz-RJ / Evaluation of ovary vitrification technique from B6D2F1 strain belonging to the Institute of Biomodels Science and Technology ICTB / Fiocruz-RJ

Objetivou-se testar a vitrificação de ovários de camundongos do ICTB/Fiocruz. Inicialmente, fez-se coleta e maturação in vitro dos oócitos de ovários a fresco e vitrificados, bem como avaliação de estruturas no cultivo embrionário, pós-fertilização in vitro. Fêmeas B6D2F1 foram eutanasiadas para remoção dos ovários (n=60) e divididas em três grupos: grupo 1 (n=30 animais) - oócito de ovários vitrificados, maturados e fertilizados in vitro (120 fragmentos); grupo 2 (n=15) (controle 1) - oócitos coletados a fresco, maturados e fertilizados in vitro; e grupo 3 (n=15) (controle 2) - oócitos maturados in vivo e fertilizados in vitro. A técnica foi verificada no desenvolvimento embrionário in vitro, que foi avaliado pelo teste de qui-quadrado (BioStat 5.0). Recuperaram-se 123, 224 e 328 oócitos nos G1, G2 e G3, respectivamente. Observaram-se diferenças significativas nas taxas de clivagem às 24 horas (embriões ≥ 2 células) entre G1 (8%) e G2 (32%) (P<0,1) e G1 e G3 (49%) (P<0,05), mas não entre G2 e G3 (P>0,05). Para blastocistos, às 96 horas, os grupos G1, G2 e G3 apresentaram, respectivamente, 6%, 11% e 46%, diferindo significativamente entre eles (P<0,05). A vitrificação de ovários, a maturação oocitária e a fertilização in vitro são alternativas para a produção de embriões de camundongos in vitro.(AU)

This work aimed test ovarian vitrification of hybrid mouse from ICTB/Fiocruz. Protocol collection and oocyte in vitro maturation from fresh and vitrified ovaries was established and embryos were evaluated after fertilization. B6D2F1 females were euthanized for ovarian removal (n= 60) and divided into 3 groups: G1 (n= 30) - ovaries fragmented (n= 120), vitrified, matured and fertilized; G2 (n= 15) - in vitro fertilization of oocytes matured in vitro from fresh ovaries; G3 (n= 15) - ampulla region oocytes in vitro fertilizated. Viability was verified by thawing, oocyte in vitro maturation and fertilization. In vitro embryo development of each group was evaluated by Chi-square test (BioStat 5.0). 123, 224 and 328 oocytes were recovered from G1, G2 and G3, respectively. Significant differences were observed in cleavage rates at 24 hours (embryos with 2 cells or more) between G1 (8%) and G2 (32%) (P< 0.1) and G1 and G3 (49%) (P< 0.05) but not between G2 and G3 (P> 0.05). Blastocysts at 96 hours presented 6%, 11% and 46%, respectively for G1, G2 and G3, differing significantly (P< 0.05). Ovary vitrification, oocyte in vitro maturation and in vitro fertilization were available for the production of in vitro mouse embryos.(AU)

Vitrificación de ovocitos en pacientes oncológicas: experiencia en clínica ivi chile y revisión de la literatura / Vitrification of oocytes in oncological patients: experience in clinica ivi chile and review of literature

La sobrevida de pacientes con cáncer ha mejorado con el tiempo, especialmente en pacientes en edad fértil. La criopreservación de los ovocitos a través de la estimulación ovárica controlada (EOC) es la técnica más frecuente de preservación de la fertilidad. El objetivo del presente estudio es realizar un análisis descriptivo de los ciclos de pacientes que, previo al tratamiento de cáncer, realizaron un tratamiento de preservación de fertilidad. Se analizaron datos demográficos como edad, diagnóstico de ingreso y resultados clínicos, tales como tipo de protocolo de estimulación utilizado, número de ovocitos obtenidos, duración de la estimulación y momento de inicio en el ciclo. Resultados: La edad promedio fue 28.9 años. La duración media de la estimulación fue de 12 días, con un promedio de ovocitos obtenidos en total de 12. Se utilizaron 2 protocolos de estimulación ovárica, obteniendo mejores resultados con el esquema de antagonistas de GnRH asociado a letrozole y doble gatillante. Respecto al momento del ciclo en que se inició la estimulación ovárica, no hubo diferencias. Conclusiones: Es posible realizar preservación de la fertilidad previo a un tratamiento oncológico con buenos resultados en pacientes jóvenes, por lo que sugerimos realizarlo en todos los pacientes con diagnóstico oncológico antes el tratamiento del cáncer. Es recomendable comenzar la estimulación ovárica en cualquier fase del ciclo ya que se obtienen los mismos resultados y permite un pronto inicio de la terapia oncológica.

Survival of patients with cancer has been improving over time, especially in young patient with fertility intention. Cryopreservation of oocytes through controlled ovarian stimulation (EOC) is the most frequent technique of fertility preservation. We analyzed the data obtained from oncological patients who attended IVI Chile between January 2008 and May 2017 in search of fertility preservation. Demographic data were obtained: age, diagnosis of admission, type of stimulation protocol used, number of oocytes obtained, duration of stimulation and pregnancy rate. Results: The average age: 28,9 years; average duration of stimulation:12 days. Number of oocytes obtained in total: 12. Two ovarian stimulation protocols were used. The one with the best results was the protocol with GnRH antagonists associated with letrozole and double triggering. Regarding the moment of the cycle where to start ovarian stimulation, there were no differences. Conclusions: It is possible to carry out a fertility preservation treatment prior to an oncological treatment with good results in young patients, so we suggest the preservation of fertility in all patients with an oncological diagnosis before oncological treatment. It is recommended to start ovarian stimulation at any phase of the cycle since the same results are obtained.

Vitrification-based cryopreservation of tissues: Strengths and existing problems / 中国组织工程研究

BACKGROUND: Vitrification-based cryopreservation is a promising cryopreservation method, which can change the state of the biological materials by using high concentration vitrification reagent to realize active preservation. OBJECTIVE: To review the biological principle of vitrification-based cryopreservation, the classification of cryopreservation reagents, as well as the cryopreservation of ovary skin, cornea and other medical tissue specimens. METHODS: PubMed and WanFang databases were searched for relevant articles published from January 1994 through October 2019. Search terms were “tissue; vitrification; cryopreservation” in English and Chinese, respectively. According to the inclusion and exclusion criteria, 45 articles were finally included in result analysis.RESULTS AND CONCLUSION: The process of vitrification-based cryopreservation can avoid ice crystallization by which the cells are damaged, and effectively preserve the cell’s biological activity and basic functions. Vitrified cryopreservation reagents can be divided into permeable and non-permeable reagents. Their operation is simple and efficient. The only disadvantage is that the high concentration of cryopreservation reagents can cause some toxic injuries to the cells. To reduce the risk of overall tissue damage, a variety of low-toxic cryopreservation reagents can be mixed and used. At present, vitrification-based cryopreservation technology has been successfully applied in a variety of cells. However, the technical problems in the cryopreservation of tissues have not been solved completely.

Fresh versus frozen embryo transfer: a retrospective cohort study

Background: Elective frozen embryo transfer (FET), has recently increased significantly with improvements in cryopreservation techniques. Observational studies and randomized controlled trials suggested that the endometrium in stimulated cycles is not optimally prepared for implantation; risk of ovarian hyperstimulation syndrome reduced and pregnancy rates increased following FET and perinatal outcomes are less affected after FET. However, the evidence is not unequivocal and recent randomised control trials challenge the use of elective FET for the general IVF population. Pregnancy rates were analysed in a cohort of patients undergoing embryo transfers.Methods: This was a retrospective cohort study of patients who underwent embryo transfers from April 2018 to March 2019 at study centre in Surat.175 cycles of embryo transfers (119 fresh and 56 frozen) were included in the study. Outcomes measured were positive pregnancy, clinical pregnancy and ongoing clinical pregnancy rates achieved in the IVF-ET cycles.Results: There were no statistically significant differences between positive pregnancy rate (54.6% versus 60.7%, Odds ratio (OR) 0.78; 95% Confidence Interval (CI) 0.41-1.49), clinical pregnancy rate (48.73% versus 57.14%, OR 0.52; 95% CI 0.1- 2.64) and ongoing clinical pregnancy rate  (45.38% versus 51.78% OR 1.4; 95% CI 0.29 - 6.67) in fresh ET and FET cycles, respectively, p < 0.05 was considered statistically significant for all measures.Conclusions: Despite the observed higher rates of positive biochemical, clinical and ongoing clinical pregnancy per transfer in the FET cohort, these did not reach statistical significance. Thus, both transfer strategies are reasonable options, although there is a trend favouring the freeze-all strategy.

Case reports for embryo banking: for women who want their own

Out of the many challenges in management of female factor infertility, poor responders and low response to stimulation in aged and even younger women, seems to be a common problem. It is very difficult to offer one particular management strategy or treatment protocol for optimum outcome in this group of women of poor responders. In a low resource set up, IVF (In vitro Fertilization) specialist doctors usually face a challenge in treating women with poor/ low ovarian reserve as ovum / gamete donation is considered as a taboo in various sections of society even today. Hence women insist on having an offspring of "their own" and vehemently deny ovum / gamete donations. In this article we discuss 2 cases of poor ovarian reserve retrospectively, who underwent multiple cycles of controlled ovarian hyperstimulation for embryo banking and ultimately achieved pregnancy. Both patients achieved pregnancy with the method of embryo banking. Embryo banking should be considered and discussed. Various articles have discussed the advantages and disadvantages of embryo banking or even oocytes accumulation. The advantages of this technique is patients with poor/low ovarian reserve get a chance to be pregnant with their own oocytes and also have a chance for vitrification of residual embryos. Another advantage in such patients is that the embryos can undergo PGS (Preimplantation Genetic Screening) techniques in cases of suspected genetic disorders. The disadvantage in a low resource set up like India is the cost of the treatment. Nevertheless, embryo banking and accumulation of oocytes should be given as an option for treatment of poor/ low ovarian reserve and could be considered as a ray of hope for all future mothers hoping for a child of "their own".

Does Overnight Culture of Cleaved Embryos Improve Pregnancy Rate in Vitrified-Warmed Embryo Transfer Programme?

@#Background: Vitrification is a routine procedure in assisted reproductive technique (ART) lab. However, there is widespread variability between protocols of different centres. The aim of this study was to compare the chemical pregnancy, clinical pregnancy and live birth rates between one-day embryo culture and immediate transfer for frozen-thawed embryo transfer (FET) cycles. Methods: In this cohort retrospective study, 366 FET cycles were divided into two groups: Group A, the embryos were warmed one day before transfer, and were cultured overnight; Group B, the embryos were warmed on the same day of transfer, at least were cultured 1 h before embryo transfer (ET). Chemical and clinical pregnancy and live birth rates were compared between two groups. Results: The chemical pregnancy was higher in group A than B (37.9% versus 28.9%), but this difference was not significant (P = 0.07). Clinical pregnancy (30.8% versus 24.1%) and live birth (19.8% versus 22.05%) were similar in group A and B, (P = 0.15), and (P = 0.8). Conclusion: In conclusion, overnight culture and confirmation of mitosis resumption was not essential for FET cycles in vitrification method.

Experimental study on high throughput vitrification by micro-droplet spray method / 生物医学工程学杂志

There is a great demand for blood and stem cells in clinic. It is difficult to achieve high throughput and to increase the cooling rate at the same time during vitrification. In this paper, a micro-droplet spray system with a container collection device was fabricated, and HepG2 cells were sprayed by this system for high-throughput vitrification. First, the container collection device and a cryo-paper were used to receive micro-droplets in the spray vitrification system. The results showed that the cell survival rate and 24h adhesion rate in container collection vitrification group were significantly higher than those in cryo-paper collection group. Second, HepG2 cells were sprayed and vitrified at increased cell density, and it was found that the results of micro-droplet spray vitrification did not change significantly. Finally, micro-droplet spray vitrification is compared with slow freezing. Cell processing capacity in the vitrification group increased, meanwhile, the cell survival rate and 24h adhesion rate in the vitrification group were significantly higher than those in slow freezing group. The results indicated that the micro-droplet spray vitrification system with container collection device designed in this paper can achieve high-throughput cell vitrification, which is of great significance for mass preservation of small cells.

Causes of oocyte vitrification and its value in assisted reproductive technology / 南方医科大学学报

OBJECTIVE@#To explore the causes of oocyte vitrification and its application in assisted reproduction.@*METHODS@#We retrospectively analyzed the data of 26 patients with 27 cycles of oocyte vitrification cryopreservation undergoing intracytoplasmic sperm injection (ICSI) and embryo transfer between January, 2008 and October, 2018. The causes of oocyte vitrification and the outcomes of ICSI and clinical pregnancy were analyzed.@*RESULTS@#The causes of oocytes vitrification included mainly azoospermia or severe spermatogenesis disorder of the husband, failure to obtain sperms from the husband, failure of the husband to be present on the day of oocyte retrieval and acute diseases of the husband to not allow sperm collection. A total of 274 oocytes were frozen in 27 oocyte retrieval cycles, and 217 eggs were thawed in 19 cycles with a survival rate of 81.11% (176/217). The normal fertilization rate, cleavage rate and high-quality embryo rate was 74.81% (98/131), 89.80% (88/98) and 36.73% (36/98), respectively. Fifteen patients underwent embryo transfer, and the clinical pregnancy rate and live birth rate was 53.33% (8/15) and 33.33% (5/15), respectively. Compared with patients below 35 years of age, the patients aged above 35 years had significantly lower oocyte survival rate after thawing (82.76% 74.42%, =0.211), clinical pregnancy rate (77.78% 16.67%, =0.041) and live birth rate (55.56% 0, =0.044).@*CONCLUSIONS@#Oocytes vitrification can be used as a remedy for infertile couples who fail to provide sperms due to male factors on the day of oocyte retrieval. Vitrification of the oocytes does not significantly affect the fertilization rate or the clinical pregnancy rate. The survival rate of the thawed oocytes is related to the age of the wife, and an age younger than 35 years can be optimal for achieving favorable clinical pregnancy outcomes after oocyte vitrification.

Survival of isolated human preantral follicles after vitrification: Analyses of morphology and Fas ligand and caspase-3 mRNA expression / 대한생식의학회지

OBJECTIVE: This study aimed to examine the effect of vitrification on apoptosis and survival in human preantral follicles after thawing.METHODS: This experimental study was conducted at an acute tertiary care hospital from March 2012 to April 2013. Ovaries were sliced into 5×5×1-mm pieces and divided into the following three groups: preantral follicle isolation, ovarian tissue vitrification-warming followed by follicle isolation, and immunohistochemistry of fresh ovarian tissue. For statistical analyses, the Student t-test, chi-square test, Kruskal-Wallis test, and Kaplan-Meier survival analysis were used.RESULTS: A total of 161 preantral follicles (70% secondary) were collected from ovarian cortex tissue of six women between 30 and 37 years of age who underwent oophorectomy due to cervical cancer or breast cancer. There were no significant differences in the follicular morphology of fresh preantral follicles and vitrified follicles after thawing. The mean Fas ligand (FasL) mRNA expression level was 0.43±0.20 (relative to β-actin) in fresh preantral follicles versus 0.51±0.20 in vitrified follicles (p=0.22). The mean caspase-3 mRNA expression level in fresh preantral follicles was 0.56±0.49 vs. 0.27±0.21 in vitrified follicles (p=0.233). One vitrified-thawed secondary follicle grew and developed to an antral follicle within 6 days of culture.CONCLUSION: Vitrification did not affect preantral follicle morphology or mRNA expression of the apoptosis markers FasL and caspase-3. Further studies are required to establish whether vitrification affects the outcomes of in vitro culture and the maturation of preantral follicles.