Antibiotics are probably second most common medications used in pregnancy. Tooth extraction is the perfect example. Every practicing obstetrician is receiving 2 to 3 such calls per year from the pregnant patient or her dentist.
The antibiotics penicillin, erythromycin, and cephalosporins (such as Keflex) are generally safe to use during pregnancy. Macrodantin (Macrobid) may be used, if necessary.