Thank you for asking at Ehealth forum!
I read your question and I understand your concern.
Syphilis could cause sterilization and can be transmitted sexually.Be sure he is free from that and other STDs also,if you have any plan for him.
I hope it helps. Stay in touch with your healthcare provider for further guidance as our answers are just for education and counseling purposes and cannot be an alternative to actual visit to a doctor.
Take care