One of my patients about 34 years old male, married for the last 3 years, so far no issue. His wife has left him on the ground that the boy is impotent. His in laws want a certificate from the doctor, declaring him potent.

On examination I find physically everything normal, erection normal. History wise also everything is okay. Can we declare a person potent from these findings or we have to subject the person to some tests etc?