This patient support community is for discussions relating to
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puberty, and any other pediatric health issues including brain, bone, heart, lungs, gastrointestinal and urological in adolescents, infants, newborns, and toddlers.
If he does in fact only have one testicle, the chances of having children is lowered. This does not mean it is impossible though. I would ask his doctor at his next appointment. Or, you could make an appointment just to get some answers.