I'm 30 years old and I have very small testicles ...

I am 30 years old and I have very small testicles. I would like to know if this can interfere with the quality of my sperm, since I am trying to have a child for a year and my wife does not become pregnant. Note: My wife already has a child from another marriage.
Expert answer:

It can interfere, yes. There is only one way for you to know: take a test called a spermogram.