Can herpes simplex i (lip herpes) affect pregnancy?

Not typically: The stress of pregnancy on your body could help produce recurrent herpes blisters. The active virus is thought to be limited to the area and not systemically, so little concern is given to your developing baby. Be careful with active lesions after the baby is born, as the virus is very infectious from your lips to the child. No kissing of that precious gift when you have blisters! :).