X-Message-Number: 24168 From: "Basie" <> Subject: Better news Date: Sun, 30 May 2004 00:14:14 -0400 I guess if 70% of embryos survive freezing now then with future techniques closer to 100% could be possible. Basie It is common that during IVF/ICSI treatment more embryos are produced than are required at the time. Embryos that are surplus to requirement, assuming they are of sufficient "quality", can be successfully frozen and stored for years. Surplus embryos that are not of sufficient good quality are either allowed to perish or used for research with appropriate consent. Initial maximum duration of storage is 5 years, although this can be extended to 10 years. Couples need to maintain contact with the clinic during the time of storage. Such embryos can be thawed and replaced at a future date thus allowing a further chance for pregnancy (or another pregnancy) from the eggs collected during original treatment. It reduces the need for repeated "fresh" IVF/ICSI cycles with ovarian stimulation and egg retrieval. The first successful FET cycle was performed in 1983 and many babies have been born with this technique since. No greater risk of abnormalities than that expected from normally conceived children has been reported. Frozen-thawed embryos may be replaced in a natural cycle (without the use of drugs) or in a cycle controlled by hormonal replacement (HRT cycle). About 70% of embryos survive the freezing process and retain their viability. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=24168