Agree with Jamie. If the wife is perfectly fine, then the husband should also go for the check up. It takes both man and woman to create a baby and logically, if one (or both) isn't functionally right, it would be hard to get pregnant.
Get a gynae's help, and consider external options such as IVF (In Vitro Fertilization) and Singapore government do give subsidized treatments for married couples.
http://www.heybaby.sg/havingchildren/acp.html