Male Fertility

Background

Case 1:
A woman would like her prospective groom to be tested for fertility before marrying him. This is because his previous marriage was childless and this woman would like to eliminate the possibility that the groom was the cause of this.

Case 2:
While young, a boy successfully overcame leukemia via chemotherapy. Now many years later his prospective bride would like his fertility tested before she agrees to marry him.

Case 3:
A man engaged to be married is diagnosed as suffering from cancer. The necessary chemotherpy will render him infertile. He would like to deposit sperm in a sperm bank for use after marriage.

Question
Regarding Cases 1 & 2 may the prospective grooms give sperm for fertility testing? And if so how may this be performed within the Halacha? With respect to Case 3, may he deposit sperm in a sperm bank? If so, what method should be used to extract the sperm?

Answer
These cases were presented to Rav Eliyashiv, shlit"a. He ruled that regarding Cases 1 & 2 removing sperm is prohibited as it falls under the interdiction of wasting sperm. In Case 3, he permitted the extraction of sperm, but not manually. He suggested that electrical stimulation be used.