Basic and Clinical Approaches for Fertility Preservation and Restoration in Cancer Patients.

As gonadotoxic adverse effects of antineoplastic treatments can result in infertility, gamete cryopreservation is routinely offered to patients as the strategy to preserve their fertility. However, there are many cases where gold standards cannot be applied, as is the case for prepubertal cancer patients and others unable to produce gametes or their precursors at the moment of diagnosis. With an increasing number of cancer survivors in our society, strategies using either cryopreserved gonadal tissue or stem cells have been developed to allow cancer survivors to achieve fatherhood, and recent advances in the field have increased public interest. In this review, we discuss the latest updates in fertility preservation from a basic and a clinical point of view.

[Artificial insemination with donor sperm in the Netherlands: future-proof?]. / Kunstmatige inseminatie met donorsperma in Nederland: toekomstbestendig?

In recent years much has changed in care for artificial insemination with donor sperm (AID). Since new laws and regulations were implemented, a large number of sperm banks have closed and the total number of sperm donors and their availability have decreased. Long waiting times and the use of sperm donors recruited by foreign commercial sperm banks can indicate a shortage of sperm donors. The fact that the internet offers women the possibility of ordering donor sperm and starting treatment without the intervention of a sperm bank means that future donor-conceived children may be prevented from obtaining the identity of their sperm donor as stipulated in the Dutch law on donor information in the context of artificial insemination. In order to comply with this law, an active recruitment policy is needed for Dutch sperm donors, to prevent waiting lists and treatments outside Dutch sperm banks. Only then can current AID care be guaranteed in the Netherlands in the future.

A national study of the provision of oncology sperm banking services among Canadian fertility clinics.

The purpose of this study was to survey the current state of oncology sperm banking services provided by fertility clinics across Canada. A total of 78 Canadian fertility facilities were invited to complete a questionnaire related to the availability, accessibility, affordability and utilisation of sperm banking services for cancer patients. The total response rate was 59%, with 20 (69%) in vitro fertilisation clinics and 26 (53%) other fertility centres returning the survey. A total of 24 responding facilities accepted oncology sperm banking referrals. The time frame to book the first banking appointment for 19 (79%) facilities was within 2 days. Inconsistent practice was found regarding the consent process for cancer patients who are of minority age. Eight (33%) facilities did not provide any subsidy and charged a standard banking fee regardless of patients' financial situations. Overall, the utilisation of oncology sperm banking services was low despite its availability and established efficacy, suggesting that Canadian cancer patients are notably underserved. The study has highlighted some important issues for further consideration in improving access to sperm banking services for cancer patients, especially for adolescents. Better collaboration between oncology and reproductive medicine to target healthcare providers would help to improve sperm banking rates.

History of commercializing sexed semen for cattle.

Although the basic principles controlling the sex of mammalian offspring have been known for a relatively long time, recent application of certain modern cellular methodologies has led to development of a flow cytometric system capable of differentiating and separating living X- and Y-chromosome-bearing sperm in amounts suitable for AI and therefore, commercialization of this sexing technology. After a very long history of unsuccessful attempts to differentiate between mammalian sperm that produce males from those that produce females, a breakthrough came in 1981 when it was demonstrated that precise DNA content could be measured. Although these initial measurements of DNA content killed the sperm in the process, they led to the ultimate development of a sperm sorting system that was capable, not only of differentiating between live X- and Y-sperm, but of sorting them into relatively pure X- and Y-sperm populations without obvious cellular damage. Initial efforts to predetermine the sex of mammalian offspring in 1989 required surgical insemination, but later enhancements provided sex-sorted sperm in quantities suitable for use with IVF. Subsequent advances in flow sorting provided minimal numbers of sperm sufficient for use in AI. It was not until the flow cytometric sorting system was improved greatly and successful cryopreservation of sex-sorted bull sperm was developed that efficacious approaches to commercialization of sexed semen could be implemented worldwide in cattle. A number of companies now offer sex-sorted bovine sperm. Innovative approaches by a diverse group of scientists along with advances in computer science, biophysics, cell biology, instrumentation, and applied reproductive physiology provided the basis for commercializing sexed semen in cattle.

Avances en reproducción humana asistida. La (r)evolución lleva tiempo / No disponible

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