They won't find out if baby is deaf until they do the hearing test at the hospital after baby is born.
Well they check baby's hearing once born. And the mental retardation you should ask your doctor.
Also was your bf born deaf or was is causes by something else?
deafness isn't necessarily genetic, so I wouldn't stress about it too much. just keep taking care of yourself and look forward to all the fun you'll have with that precious baby!
He doesn't know if he was born deaf or became deaf his family is from Mexico and knows no sign language so they cant communicate and I'm fine with having a deaf baby the thought just popped to mind