Freezing of embryos
Since 1983 surplus embryos have been frozen and stored for later thawing and transfer.
Pregnancies following this procedure do not carry enhanced risk of abortion, chromosome abnormalities or malformations.
Danish legislation states:
Frozen embryos can only be used if both the woman and the man consent on thawing in writing.
Embryos can only be kept frozen until the day the woman turns 46 years old. After this time the embryos will be destroyed without warning. Embryos will also be destroyed in case of death of one of the partners or in case of dissolution of the partnership.
Before freezing the embryos, you must concede your written agreement to freezing and storing and declare that you consent to applying terms and conditions.
Embryos may only be thawed and applied if you give your written consent for the procedure.
Viable surplus embryos (25% of total embryos) can be frozen if they are suitable.
All surplus embryos will be cultured to the blastocyst stage. Only blastocysts with regular and stable divisions can survive freezing. About 5-10 % of the frozen blastocysts will be damaged during the freezing/warming process.
The blastocysts will be warmed on the day prior to the scheduled transfer into the uterus. The chance to become pregnant with frozen/warmed blastocysts is the same as with the transfer of fresh embryos.