Someone mentioned STDs, that's important. Why ... because the one std that would definitely be an issue during pregnancy is herpes. For women that nasty, burning sore they get is often in the birth canal. If your herpes is active during the baby's birth the doctors would probably take the baby by caesarian rather than expose the baby to the virus. There is no known cure as of yet for herpes, so it is "for life" once you get it. So, maybe think "condoms" to play it safe as one can still get the herpes virus even when the nasty sore is not present.