National Survey on the Status of Embryo Freezing for Fertility Preservation in Japan.

PURPOSE: No studies regarding embryo freezing as a technique for preserving fertility among patients with cancer have been conducted in Japan. Hence, we surveyed embryologists working at fertility preservation facilities to investigate the current status of embryo freezing for fertility preservation in patients with cancer in Japan.

METHODS

Embryologists from 622 institutions registered for in vitro fertilization and embryo transfer with the Japan Society of Obstetrics and Gynecology were surveyed online about their embryo freezing practices.

RESULTS

The survey revealed that 352 institutions perform embryo freezing for general assisted reproduction, while only 178 (50.6%) do so for fertility preservation. About 23.0% use different criteria or personnel for cryopreservation based on purpose, 15.2% freeze pronuclear stage embryos, 84.3% freeze cleavage stage embryos, and 92.7% freeze blastocyst stage embryos. All institutions use vitrification, and over 90% follow the manufacturer's protocol for freezing and thawing.

CONCLUSIONS

Fertility preservation through embryo freezing is not widely used in Japan, and there is inadequate data on the therapy's current status and results for patients with cancer. Further research is necessary to provide patients with cancer with the opportunity to preserve their fertility without major concerns and ultimately enhance their quality of life after treatment.