In Vitro Microvibration Increases Implantation Rate After Embryonic Cell Transplantation

Micro-vibration results in vitro-derived bovine blastocysts with greater cryotolerance, epigenetic abnormalities, and a massive transcriptional change

Much effort has been employed to improve the quality of embryos obtained by in vitro production (IVP) given the relevance of this technology to current livestock systems. In this context, dynamic IVP systems have proved beneficial to the embryo once they mimic fluid flows and mechanical forces resulting from the movement of ciliated cells and muscle contraction in the reproductive tract. In the present study, we sought to confirm these initial findings as well as assess potential molecular consequences to the embryo by applying micro-vibration (45 Hz for 5 s once per 60 min) during both oocyte maturation and embryo culture in cattle. As a result, micro-vibration led to lower incidence of apoptosis in blastocysts following vitrification-thawing. Further analyses revealed epigenetic and transcriptional changes in blastocysts derived from the micro-vibration treatment, with a total of 502 differentially expressed genes. Enrichment analyses linked differentially expressed genes to 'Oxidative phosphorylation', 'Cytokine-cytokine receptor interaction', and 'Signaling pathways regulating pluripotency of stem cells'. Yet, a meta-analysis indicated that the transcriptional changes induced by micro-vibration were not toward that of in vivo-derived embryos. In conclusion, micro-vibration increases the cryoresistance of bovine embryos, but caution should be taken given the unclear consequences of epigenetic and transcriptional abnormalities induced by the treatment.

Effects of microvibration stimulation on developmental potential of discarded germinal vesicle oocytes of human

OBJECTIVE

This research aims to study the effects of continuous microvibration stimulation on the parthenogenetic development of human germinal vesicle oocytes.

METHODS

Ninety-five discarded germinal vesicle oocytes from intracytoplasmic sperm injection treatment (ICSI) cycles performed at Amcare Women's & Children's Hospital between January and December 2021 were used for conventional static culture as well as 10 Hz microvibration culture. We investigated the differences between the two groups in terms of oocyte maturation rate, parthenogenetic activation rate, and parthenogenetic blastocyst formation rate.

RESULTS

The static culture and 10 Hz microvibration culture of 95 oocytes showed that the parthenogenetic blastocyst formation rate in the microvibration culture group was significantly higher than those in the traditional static culture group.

CONCLUSION

A continuous microvibration stimulation can significantly improve the parthenogenetic developmental potential of human immature oocytes.

Improvement of embryonic development and clinical outcomes of germinal vesicle stage oocytes using a microvibration culture system

In vitro maturation (IVM) has evolved as a clinical treatment option in assisted reproductive technology. However, the poor developmental potential of germinal vesicle (GV)-stage oocytes is still suboptimal. This study's objective was to evaluate the effect of a microvibration culture system (MVC) during IVM and/or in vitro culture (IVC) on the clinical outcomes and the embryonic development potential of human GV-stage oocytes collected from human chorionic gonadotropin (HCG)-primed IVM and fertilization-embryo transfer (IVM/F-ET) cycles of patients with polycystic ovaries (PCO). A total of 206 HCG-primed IVM/F-ET cycles were divided into four groups according to the microvibration and static culture system applied during IVM and/or IVC: Group SS (static system during both IVM and IVC); Group SV (static system during IVM alternated with microvibration system during IVC); Group VS (microvibration system during IVM alternated with static system during IVC), and Group VV (microvibration system during both IVM and IVC). The results indicate that the rates of in vitro MII oocytes per cycle, fertilization, and cleavage were not significantly different between the groups. The rate of good-quality embryos in Group SV tended to be higher than the rate in Groups SS and VS, but there was no significant difference between Group SS and Group SV. Clinical pregnancy, implantation, and live birth rates of Groups SV and VS were slightly higher than those of Group SS. However, the rate of good-quality embryos with at least six cells on day 4, the clinical pregnancy, implantation, and live births in Group VV were significantly higher than those in Group SS. These results indicate that, compared with the static culture system, the MVC system applied for both IVM and IVC seems to improve the clinical outcomes and the quality of embryos of GV oocytes derived from HCG-primed IVM/F-ET cycles in PCO patients. Abbreviations: PCO: polycystic ovaries; HCG: human chorionic gonadotropin; GV: germinal vesicle; MII: metaphase II; IVM: in vitro maturation; IVF: in vitro fertilization; IVC: in vitro culture: MVC: microvibration culture; SC: static culture; ICSI: intracytoplasmic sperm injection; IVM/F-ET: IVM and fertilization-embryo transfer; AMH: anti-Mullerian hormone; OHSS: ovarian hyperstimulation syndrome.

Effect of Mechanical Microvibration on the Quality of Human Embryos during In Vitro Culturing and Outcomes of Assisted Reproduction Technologies

We summarized the data on the role and efficiency of mechanical microvibration during embryo culturing in assisted reproduction protocols. The efficiency of culturing systems with microvibration in assisted reproduction programs and possible mechanisms of microvibration effect on the preimplantation development of human embryos are discussed.

"Naturalization" of Routine Assisted Reproductive Technologies by In Vitro Culture of Embryos with Microvibration: Sex Ratio, Body Length, and Weight of 2,456 Live-Birth Deliveries after Transfer of 9,624 Embryos In Vitro Cultured in Static System and with Microvibration

Aim was to determine whether there is any difference in the sex ratio, body length, and body weight of 2,456 deliveries after transfer of 9,624 embryos derived using in vitro culture under static and mechanical microvibration conditions. Pronuclear embryos from 4435 patients were cultured in vitro under two different conditions: without (n = 4821) and with mechanical agitation (n = 4803). Sex ratio, body length, and weight of 2,456 live-birth deliveries after transfer of 9,624 embryos were noted. The proportion of males at birth was significantly associated with mode of in vitro culture of embryos only among women aged 40 years and older. The rate "body length" was significantly associated with mode of in vitro culture of embryos only among women aged 29 and younger. In the same time, among twins, this ratio positively associated with in vitro culture of embryos under microvibration only among women aged 30-34 years as well as ≥40 years and negatively among women aged 35-39 years. It was concluded that birth weight of infants was positively associated with mode of in vitro culture of embryos under microvibration among women of all age groups. This trial registration number is ISRCTN13773904, registered 6 April 2016.