Harav Professor Halperin
I have a theoretical question, which I thought you may be able to assist me with.
If a man dies childless, his widow and unmarried brother would normally have to undergo the ceremony of chaliza-yibum.
If the couple had frozen sperm stored, with the intention of fertility treatment, would chaliza still be necessary.
Or alternatively could sperm could even be taken from the dying man, in order for their to be a possibility of future children, thus not necessitating chaliza.
If a widow has to undergo chalizo and yibum, the fact that the couples has frozen sperm or even frozen embryo does not change their halachic status, even if a child will be born afterwards.
A full discussion on this question may be seen in my "Medicine, Nature and Halacha" (Heb.) pp. 311-332.
Only if the woman is pregnant at the time of her husband's death, the chaliza and yibum is suspended until the birth, so that if a viable offspring will be born there will be no need for chaliza or yibum.