I am 38 years old and my husband is 64 years old, I want to have a baby

I am 38 years old and my husband is 64 years old.He has diabetes and glaucoma.I really want to have a baby,4 months now I'm trying to get pregnant but no luck,he has kids from his ex and I have a child from previous marriage too,we have a good sex life but because of his age and diabetes,is he still capable of getting me pregnant?Thanks in advance.