There are some infections that can only be cured with an antibiotic. If the antibiotic is not taken, the infection could worsen and harm mom, baby, or both. Not all illnesses are infections that need to be treated with antibiotics. Viruses and fungal infections cannot usually be treated using antibiotics but other medications.
The obstetrician will judge the severity of the infection before prescribing an antibiotic. Due to the increasing desensitization of the human body to antibiotics, many doctors either try to allow the body to fight off the infection before prescribing antibiotics or try to treat the infection by other means before using an antibiotic. If there is no other option, the doctor will choose an antibiotic in Category A, B, or C. These antibiotics are considered the safest for use during pregnancy. If the infection cannot be treated with an antibiotic on either of these category lists, an antibiotic will be used from Category D.
If the pregnant woman presents with a fungal or bacterial infection, a medication will be chosen to treat that infection. This medication will not be an antibiotic. Antifungal and antibacterial medications are also divided into Categories A, B, C, D and X. Again, the doctor will choose the appropriate medication from Category A or B or C whenever possible.
No medications should be taken while pregnant unless prescribed by the obstetrician or a doctor that understands you are currently pregnant. This is especially important during the first trimester when the organs are forming in the fetus.