Question: why do you freeze the sperm?

Laura Wales answered on 17 Jun 2015:

I freeze sperm to preserve fertility. Sometimes a guy will have trouble producing a sperm sample on the day his wife/partner is ready for IVF treatment, other times it’s because sperm numbers are so low that we need multiple samples for IVF.

More often, I freeze sperm for cancer patients about to start chemo or radiotherapy and patients about to start drug therapy that could affect their future fertility. Sometimes these men are left permanently infertile but because I freeze their sperm, it gives them and their partner the chance of having a baby of their own in the future.

Sometimes I freeze sperm for transgender patients who are biologically male but are about to start taking female hormones.