Researching human oocyte cryopreservation: ethical issues

An Update on Planned Oocyte Cryopreservation (POC) in Italy: Medical, Epidemiological and Legal Consideration

Starting with a brief socioeconomic analysis of the phenomenon of female fertility, this narrative review aims to provide an analysis of the use and possibilities of medically assisted reproductive technology in combating fertility issues, adopting socioeconomic, legal and medical perspectives in Italy. The authors mainly employ data from the annual reports of the National Registry of Medically Assisted Reproduction (PMA Registry) and the Italian Statistical Institute (ISTAT) to understand the evolution of oocyte use in medically assisted reproductive technology in Italy from 2015 to 2018 and in particular to dissect the possibilities of oocyte cryopreservation as a measure to counteract age-related infertility, specifically through Planned Oocyte Cryopreservation (POC), also known as "social freezing". It seems that the best course of action in the context of medically assisted reproduction would be the use of young and healthy cryopreserved oocytes (autologous or donated), preferably before the age of 40, while encouraging donation of oocytes whenever possible. Italy's dependence on foreign biobanks for donated oocytes calls for the institution of a national biobank and further specific regulation of gamete donation. For this reason, it would be useful to encourage the acceptance of Planned Oocyte Cryopreservation to allow greater availability of healthy, younger oocytes.

Impact of vitrification on the meiotic spindle and components of the microtubule-organizing center in mouse mature oocytes

Cryopreservation of oocytes is becoming a valuable method for fertility preservation in women. However, various unphysiological alterations occur in the oocyte during the course of cryopreservation, one of which is the disappearance of the meiotic spindle. Fortunately, the meiotic spindle does regenerate after thawing the frozen oocytes, which enables completion of meiosis and further development after fertilization. Nonetheless, the mechanistic understanding of the meiotic spindle regeneration after cryopreservation is still scarce. Here, to gain insight into the mechanisms of the spindle disappearance and regeneration, we examined the status of spindle microtubules as well as the key components of the microtubule-organizing center (MTOC), specifically gamma-Tubulin, NEDD1, and Pericentrin, in mature (metaphase II) mouse oocytes at different steps of vitrification, a major cryopreservation technique. We found that the configuration of the spindle microtubules dynamically changed during the process of vitrification and that spindle regeneration was preceded by excessive microtubule polymerization, followed by reduction into the normal size and shape. Also, all three MTOC components exhibited disappearance and reappearance during the vitrification process, although Pericentrin appeared to regenerate in earlier steps compared to the other components. Furthermore, we found that the localization of the MTOC components to the spindle poles persisted even after depolymerization of spindle microtubules, suggesting that the MTOC components are impacted by vitrification independently from the integrity of the microtubules. The present study would set the stage for future investigations on the molecular mechanisms of the meiotic spindle regeneration, which may contribute to further improving protocols for oocyte cryopreservation.

Freezing the Biological Clock: A Viable Fertility Preservation Option for Young Singaporean Women?

In March 2012, an article in The Straits Times entitled ‘Freezing eggs could reverse falling birth rate’ suggested that employing the latest oocyte cryopreservation techniques could both foster individual women’s reproductive autonomy and impact Singapore’s fertility rate, which in recent years has consistently been among the world’s lowest. The article cited both local and international fertility specialists’ approval of elective oocyte cryopreservation for young women wishing to protect their reproductive potential against ageing and as a potential antidote to the contemporary ‘delay and defer’ model of family-building. Later in 2012, the Ministry of Health announced a review of oocyte cryopreservation policy taking into account related medical, scientific and ethical issues, while the Singapore College of Obstetricians and Gynaecologists endorsed oocyte cryopreservation as an “important, safe and efficient technology”. This paper outlines and analyses the arguments and empirical evidence used both to support and oppose offering elective oocyte cryopreservation as a routine fertility service, before concluding that this remains unjustifiable on the basis of insufficient evidence of its clinical efficacy and safety as regards either pregnancy rates or birth outcomes. If it is to be made available at all for these reasons in Singapore, it should be subjected to rigorous clinic-specific evaluation in accordance with accepted clinical and ethical norms. Key words: Elective oocyte cryopreservation, Outcomes

Ethical issues in health-care inquiry: a discussion paper

This paper is a discussion of the possible ethical dilemmas that may arise in both qualitative and quantitative research despite stringent methodological protocols. Three categories of ethical issues will be elaborated on, namely, researcher-participant relations, informed consent and confidentiality and privacy. These are of note because ethical dilemmas most often arise in these areas. Both qualitative and quantitative research types may thus present with problems associated with any, or a combination, of these categories. Methodological rigour will also be discussed as a vital component of any research study. Critics of the qualitative approach have often suggested that the innate lack of methodological rigour has resulted in the preponderance of ethical issues in qualitative studies. Qualitative studies, similar to quantitative studies, have mechanisms that guarantee rigour, quality and trustworthiness. These checks are at par with those of quantitative research but based on different criteria. Both types of research, then, can be considered equal in terms of methodological rigour, regardless of the nature. As no research approach can be perfectly free from threats of ethical issues, it is the researcher's responsibility to address these in ways that will be less harmful to the participants, bearing in mind ethical problems can arise at any time during the research endeavour.

Microtubule organisation, pronuclear formation and embryonic development of mouse oocytes after intracytoplasmic sperm injection or parthenogenetic activation and then slow-freezing with 1,2-propanediol

The goal of this study was to investigate the effect of cryopreservation on oocytes at different times after intracytoplasmic sperm injection (ICSI) and parthenogenetic activation. The study was performed in mouse oocytes fertilised by ICSI, or in artificially-activated oocytes, which were cryopreserved immediately, one hour or five hours later through slow-freezing. After thawing, the rates of survival, fertilisation–activation, embryonic development of oocytes–zygotes and changes in the cytoskeleton and ploidy were observed. Our results reveal a significant difference in survival rates of 0-, 1- and 5-h cryopreserved oocytes following ICSI and artificial activation. Moreover, significant differences in two pronuclei (PN) development existed between the 0-, 1- and 5-h groups of oocytes frozen after ICSI, while the rates of two-PN development of activated oocytes were different between the 1-h and 5-h groups. Despite these initial differences, there was no difference in the rate of blastocyst formation from two-PN zygotes following ICSI or artificial activation. However, compared with ICSI or artificially-activated oocytes cryopreserved at 5 h, many oocytes from the 0- and 1-h cryopreservation groups developed to zygotes with abnormal ploidy; this suggests that too little time before cryopreservation can result in some activated oocytes forming abnormal ploidy. However, our results also demonstrate that spermatozoa can maintain normal fertilisation capacity in frozen ICSI oocytes and the procedure of freeze–thawing did not affect the later development of zygotes.

Bibliography. Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 February 2008 and 31 January 2009 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.

The Human Oocyte Preservation Experience (HOPE) a phase IV, prospective, multicenter, observational oocyte cryopreservation registry

BACKGROUND

It has been recommended by the American Society of Clinical Oncology and the American Society of Reproductive Medicine that options to preserve fertility be presented at the outset of treatment for cancer. This recommendation may have arisen, in part, to the increasing survival of patients with cancer and the realization that certain forms of cancer treatment can lead to infertility. One option for these patients, particularly those with ethical or religious objections to freezing embryos is oocyte cryopreservation. However universal acceptance of these procedures has yet to be established, most likely due to a poor history of success and concerns that there has yet to be a comprehensive approach to evaluating these techniques. In light of this, a registry of patients undergoing oocyte cryopreservation, called the HOPE registry, is being implemented.

DISCUSSION

The intent of the HOPE Registry is to enroll approximately 400 women of reproductive age who will undergo thawing/warming of oocytes and subsequent transfer. Data from the patients enrolled will be collected via a uniform, standardized form and will document important parameters such as demographics, laboratory procedures and outcomes, including following the outcomes of babies born for one year after birth. The results of the registry will be published on a yearly basis.

SUMMARY

A patient registry has been established in order to systematically document the techniques and outcomes of oocyte cryopreservation procedures. The results will be published in order to provide a widely accessible resource that will allow patients who are considering these procedures validated information in order to make informed decisions as to how their treatment will proceed.