Dataset Information

Improving the maturation rate of human oocytes collected ex vivo during the cryopreservation of ovarian tissue.

ABSTRACT:

Purpose

The aim of the present study was to improve the in vitro maturation (IVM) procedure using oocytes from surplus ovarian tissue after fertility preservation.

Methods

Twenty-five patients aged 17-37 years were included in the study. Maturation was compared between oocytes collected in HEPES-buffered medium or saline, and we determined whether transport on ice prior to oocyte collection affected maturation. Two different IVM media were used that were supplemented with and without recombinant human midkine. Mature oocytes were assessed for aneuploidy using next-generation sequencing (NGS).

Results

On average, 36 immature oocytes were collected from each patient (range 7-90, N = 895). Oocytes recovered from HEPES-buffered medium matured at a higher rate than oocytes recovered from saline (36% vs 26%, p < 0.01). Ovarian transportation on ice prior to the procedure negatively affected maturation compared with non-transported samples (42% vs 27%, p < 0.01). The addition of midkine improved maturation rate (34% vs 27%, p < 0.05). On average, 11 MII oocytes were obtained per patient (range 1-30). NGS of 53 MII oocytes and their first polar bodies indicated that 64% were euploid.

Conclusions

The study demonstrated unexpectedly high number of immature oocytes collected from surplus ovarian tissue without any stimulation. The overall MII rate was one in three, resulting in a total number of MII oocytes that was similar to the number obtained after ovarian stimulation. If these MII oocytes prove suitable for IVF, they will provide a substantial improvement in fertility preservation for patients and advance IVM as an interesting platform for further improvements in assisted reproduction.

SUBMITTER: Nikiforov D

PROVIDER: S-EPMC7183016 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

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Publications

Improving the maturation rate of human oocytes collected ex vivo during the cryopreservation of ovarian tissue.

Nikiforov Dmitry D Junping Cheng C Cadenas Jesus J Shukla Vallari V Blanshard Robert R Pors Susanne Elisabeth SE Kristensen Stine Gry SG Macklon Kirsten Tryde KT Colmorn Lotte L Ernst Erik E Bay-Bjørn Anne-Mette AM Ghezelayagh Zeinab Z Wakimoto Yu Y Grøndahl Marie Louise ML Hoffmann Eva E Andersen Claus Yding CY

Journal of assisted reproduction and genetics 20200224 4

<h4>Purpose</h4>The aim of the present study was to improve the in vitro maturation (IVM) procedure using oocytes from surplus ovarian tissue after fertility preservation.<h4>Methods</h4>Twenty-five patients aged 17-37 years were included in the study. Maturation was compared between oocytes collected in HEPES-buffered medium or saline, and we determined whether transport on ice prior to oocyte collection affected maturation. Two different IVM media were used that were supplemented with and with ...[more]

PMID: 32096110

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Project description:Study questionIs it possible to establish an ex vivo endometriosis model using cryopreserved endometriotic tissue fragments?Summary answerCryopreserved endometriotic tissue fragments remain viable after thawing and during at least 3 days of culture and can therefore be used to establish an ex vivo endometriosis model to efficiently test potential therapeutic agents.What is known alreadyEndometriosis is the most prevalent benign gynecologic disease with an enormous societal burden; however, curative therapies are still lacking. To efficiently test potential new therapies, an ex vivo model based on previously cryopreserved endometriotic tissue that recapitulates the different endometriosis subtypes and their microenvironment is highly desirable.Study design, size, durationEndometriotic tissue fragments of three different subtypes were obtained from 28 patients by surgical resection. After cryopreservation and thawing, viability and metabolic activity of these tissue fragments were assessed. Viability was compared with fresh fragments from 11 patients directly after surgical removal. Experimental intervention studies were performed in cryopreserved and thawed tissue fragments from two patients to confirm the usability of these tissues for ex vivo intervention studies.Participants/materials, setting, methodsEndometriotic tissue fragments (n = 45) were cryopreserved according to three different protocols. After thawing, fragments were cultured for 24 h. A resazurin-based assay was performed to assess the metabolic activity of the tissue fragments. In addition, cell type-specific viability was analyzed by VivaFix, Hoechst 33342, and α-smooth muscle actin immunofluorescence staining and confocal microscopy. The presence of endometriosis was histologically confirmed based on hematoxylin-eosin staining. Cryopreserved and thawed tissue fragments were treated for 72 h with pirfenidone or metformin and COL1A1 and CEMIP gene expressions were assessed using RT-PCR and RT-qPCR, either in the whole tissue fragments or in myofibroblasts isolated by laser capture microdissection.Main results and the role of chanceMetabolic activity of endometriotic tissue fragments obtained from peritoneal (PER), ovarian (OMA), and deep (DE) endometriotic lesions was well preserved after cryopreservation in a dimethyl sulfoxide-based medium and was comparable with fresh tissue fragments. Relative metabolic activity compared to fresh tissue was 70% (CI: 92-47%) in PER, 43% (CI: 53-15%) in OMA and 94% (CI: 186-3%) in DE lesions. In fragments from PE lesions 92% (CI: 87-96%), from OMA lesions 95% (CI: 91-98%), and from DE lesions 88% (CI: 78-98%) of cells were viable after cryopreservation and thawing followed by a 24-h culture period. Differences in gene expression of fibrotic markers COL1A1 and CEMIP after 72-h treatment with pirfenidone or metformin could be detected in whole tissue fragments and in isolated myofibroblasts, indicating that cryopreserved and thawed endometriotic tissue fragments are suitable for testing anti-fibrotic interventions.Large scale dataN/A.Limitations, reasons for cautionViability and metabolic activity of the endometriotic tissue fragments may have been partially compromised by damage sustained during the surgical procedure, contributing to inter-sample variance.Wider implications of the findingsThe storage of viable endometriotic tissue fragments for later usage in an ex vivo model creates the possibility to efficiently test potential new therapeutic strategies and facilitates the exchange of viable endometriotic tissue between different research laboratories.Study funding/competing interest(s)This study was not financially supported by external funding. The authors declare no competing interest.Trial registration numberN/A.

Project description:Ovarian tissue cryopreservation (OTC) is the only pre-treatment option currently available to preserve fertility for prepubescent girls and patients who cannot undergo ovarian stimulation. Currently, there is no standardized method of processing ovarian tissue for cryopreservation, despite evidence that fragmentation of ovaries may trigger primordial follicle activation. Because fragmentation may influence ovarian transplant function, the purpose of this systematic review was (1) to identify the processing sizes and dimensions of ovarian tissue within sites around the world, and (2) to examine the reported outcomes of ovarian tissue transplantation including, reported duration of hormone restoration, pregnancy, and live birth. A total of 2,252 abstracts were screened against the inclusion criteria. In this systematic review, 103 studies were included for analysis of tissue processing size and 21 studies were included for analysis of ovarian transplantation outcomes. Only studies where ovarian tissue was cryopreserved (via slow freezing or vitrification) and transplanted orthotopically were included in the review. The size of cryopreserved ovarian tissue was categorized based on dimensions into strips, squares, and fragments. Of the 103 studies, 58 fertility preservation sites were identified that processed ovarian tissue into strips (62%), squares (25.8%), or fragments (31%). Ovarian tissue transplantation was performed in 92 participants that had ovarian tissue cryopreserved into strips (n = 51), squares (n = 37), and fragments (n = 4). All participants had ovarian tissue cryopreserved by slow freezing. The pregnancy rate was 81.3%, 45.5%, 66.7% in the strips, squares, fragment groups, respectively. The live birth rate was 56.3%, 18.2%, 66.7% in the strips, squares, fragment groups, respectively. The mean time from ovarian tissue transplantation to ovarian hormone restoration was 3.88 months, 3.56 months, and 3 months in the strips, squares, and fragments groups, respectively. There was no significant difference between the time of ovarian function' restoration and the size of ovarian tissue. Transplantation of ovarian tissue, regardless of its processing dimensions, restores ovarian hormone activity in the participants that were reported in the literature. More detailed information about the tissue processing size and outcomes post-transplant are required to identify a preferred or more successful processing method.Systematic review registration[https://www.crd.york.ac.uk], identifier [CRD42020189120].

Project description:ImportancePoor ovarian response (POR) to stimulation may impact patients' desire or need to utilize cryopreserved oocytes for family building in the future. These findings, captured by Society for Assisted Reproductive Technology (SART) national data, underscore the need for tailored counseling and further research into the decision-making processes influencing oocyte utilization.ObjectiveTo examine the association of ovarian response to stimulation and the number of vitrified oocytes with the likelihood and timing of patients returning for oocyte utilization following planned oocyte cryopreservation (OC).Design, setting, and participantsThis cohort study used data in the SART Clinical Outcome Reporting System for patients in US fertility clinics and data was used for eligible patients who underwent planned OC from January 2014 through December 2020. Data were analyzed from November 2022 to June 2023.Main outcomes and measuresThe association between number of oocytes cryopreserved on return rate to utilize cryopreserved oocytes and the time from vitrification to warming.ResultsA total of 67 893 autologous oocyte freezing cycles were performed in the US between 2014 and 2020, among 47 363 patients (mean [SD] age, 34.5 [4.7] years). Of these, 6421 (13.5%) were classified as patients with POR, with fewer than 5 oocytes vitrified across all ovarian stimulation cycles. A total of 1203 patients (2.5%) returned for oocyte warming and utilization. The rate of return was significantly higher in the POR group, with 260 (4.0%) returning compared with 943 (2.3%) in the normal responder group (P < .001). This trend was most notable in the age 30 to 34 years (warm cycle, 46 of 275 [16.7%] vs no warm cycle, 982 of 11 743 [8.4%]; P < .001) and age 35 to 39 years groups (warm cycle, 124 of 587 [21.1%] vs no warm cycle, 3433 of 23 012 [14.9%]; P < .001). The time elapsed from vitrification to warming was comparable between patients with POR (mean [SD], 716.1 [156.1] days) and normal responders (803.8 [160.7] days). A multivariate analysis adjusted for age, clinic region in the US, body mass index, and history of endometriosis was conducted to identify factors associated with the utilization of oocytes. The analysis revealed that having fewer than 5 oocytes vitrified was associated with higher odds of utilizing oocytes (OR, 1.52; 95% CI, 1.32-1.76).Conclusions and relevanceThis cohort study reveals a distinct pattern in the utilization of cryopreserved oocytes among patients undergoing planned OC in the US. Despite the increase in number of patients pursuing OC, there is a notably low rate of return to utilize previously vitrified oocytes; notably, patients with POR are more likely to return, although the time to return is similar to those with normal ovarian response.

Dataset Information

Improving the maturation rate of human oocytes collected ex vivo during the cryopreservation of ovarian tissue.

Purpose

Methods

Results

Conclusions

Publications

Improving the maturation rate of human oocytes collected ex vivo during the cryopreservation of ovarian tissue.

Similar Datasets

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