What stops a man having babies?

A man typically cannot have biological children if he has infertility issues, which may stem from low sperm count, abnormal sperm function, or blockages in the reproductive system. Medical conditions such as hormonal imbalances, genetic disorders, or previous surgeries can also affect fertility. Additionally, lifestyle factors like smoking, excessive alcohol consumption, and obesity can further impact a man's ability to conceive. In cases of complete absence of sperm (azoospermia) or other severe reproductive issues, assisted reproductive technologies or adoption may be considered.