Purpose: To ascertain possible cell damage from cryopreservation, the ultrastructure of human oocytes cryopreserved by slow cooling was assessed.
Materials And Methods: Cryopreservation was performed through two protocols with one-step or two-step propanediol. Fresh control oocytes were examined for comparison. Samples were processed for transmission electron microscopy analysis.
Results: By light microscopy, both fresh and frozen-thawed oocytes appeared regularly rounded, with intact zona pellucida, and homogeneous cytoplasm. By electron microscopy observation, organelles were abundant and uniformly dispersed. Mitochondria-smooth endoplasmic reticulum associations appeared regular. However, both the amount and density of cortical granules appeared abnormally reduced in frozen-thawed samples. Slight to moderate vacuolization was also found in the ooplasm of oocytes of both frozen groups.
Conclusions: Slow cooling ensures a good overall preservation of human oocytes. However, cytoplasmic vacuolization and cortical granule loss appears associated with cryopreservation, irrespective of the protocol used.
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http://dx.doi.org/10.1007/s10815-010-9394-7 | DOI Listing |
Reprod Biol Endocrinol
January 2025
Reproductive Medicine Center, Zhuhai Maternal and Child Health Care Hospital, 543 Ningxi Road, Zhuhai, 519000, China.
Purpose: Prior sperm DNA fragmentation index (DFI) thresholds for diagnosing male infertility and predicting assisted reproduction technology (ART) outcomes fluctuated between 15 and 30%, with no agreed standard. This study aimed to evaluate the impact of the sperm DFI on early embryonic development during ART treatments and establish appropriate DFI cut-off values.
Methods: Retrospectively analyzed 913 couple's ART cycles from 2021 to 2022, encompassing 1,476 IVF and 295 ICSI cycles, following strict criteria.
Biol Res
January 2025
Clinical Research Development Unit of Tabriz Valiasr Hospital, Tabriz University of Medical Sciences, Tabriz, Iran.
Fluoride (F), as a natural element found in a wide range of sources such as water and certain foods, has been proven to be beneficial in preventing dental caries, but concerns have been raised regarding its potential deleterious effects on overall health. Sodium fluoride (NaF), another form of F, has the ability to accumulate in reproductive organs and interfere with hormonal regulation and oxidative stress pathways, contributing to reproductive toxicity. While the exact mechanisms of F-induced reproductive toxicity are not fully understood, this review aims to elucidate the mechanisms involved in testicular and ovarian injury.
View Article and Find Full Text PDFJ Assist Reprod Genet
January 2025
UMass Memorial Medical Center, Memorial Campus, 119 Belmont St, Worcester, MA, 01605, USA.
Purpose: Induction of meiotic competence is a major goal of the controlled ovarian stimulation used in ART. Do factors intrinsic to the oocyte contribute to oocyte maturation? Deletions in mtDNA accumulate in long-lived post mitotic tissues and are found in human oocytes. If oogenesis cleanses the germline of deleterious deletions in mtDNA, meiotically competent oocytes should contain lower levels of mtDNA deletions vs.
View Article and Find Full Text PDFMol Hum Reprod
January 2025
Follicle Biology Laboratory, Research Group Genetics, Reproduction and Development, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
Biphasic in vitro oocyte maturation (IVM) can be offered as a patient-friendly alternative to conventional ovarian stimulation in in vitro fertilization (IVF) patients predicted to be hyper-responsive to ovarian stimulation. However, cumulative live birth rates after IVM per cycle are lower than after conventional ovarian stimulation for IVF. In different animal species, supplementation of IVM media with oocyte-secreted factors (OSFs) improves oocyte developmental competence through the expression of pro-ovulatory genes in cumulus cells.
View Article and Find Full Text PDFGynecol Endocrinol
December 2025
Department of Reproductive Medicine, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, Shandong, China.
Oocyte maturation arrest (OMA) may occur at different stages, including the germinal vesicle (GV), metaphase I (MI), and metaphase II (MII). A total maturation arrest of human oocytes is rarely observed during fertilization (IVF). We have identified a case of infertile female for whom all oocytes fail to mature and are arrested at MI.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!