A growing number of men who want to be fathers are using sperm banks to preserve fertility

For a man who is about to die, it is perhaps the ultimate attempt at self-preservation. "Even if I must depart," the reasoning goes, "my progeny will endure." 

But just as storing sperm can, in some places, be a measure aimed at preempting death, it can also act as insurance against the inability to father children. One example is someone who is on the verge of being given medical treatment such as chemotherapy for cancer that risks rendering them infertile. 

Unlike in some countries and jurisdictions, in China the ethical and legal questions raised over whether the sperm of a man can be used to fertilize an egg after he has died are moot because once the man dies it is illegal to use the sperm.

In the case of men facing the impending risk of infertility as a result of medical treatment, sperm bank directors around China who spoke to China Daily for this article were unanimous in seeing no reason for refusing to provide their services where it is safe to do so.

However, the issue becomes a little less clear when fertility-threatening medical treatment is removed from the equation. In this scenario anyone buying into what is in effect an insurance policy may have in mind factors such as heavy air pollution that increase their risk of diseases like as cancer or the damage to health done by work stress. For such people the rationale is that it is best, while the going is good, to put sperm into the bank for use on a rainy day.