The antibiotic most often used to prevent GBS infections of newborn babies is called ampicillin. Treatment of GBS carriers has been shown to be the most effective method of preventing severe disease in newborns. Ampicillin is an extremely safe antibiotic. Since it is given only for the duration of labor, anywhere from 1 to 4 doses may be administered. The short duration of treatment reduces the risk of side effects in mothers. Treatment of the mother reduces the risk of spread of GBS to the baby during labor and delivery, thereby protecting the baby.
Although the risk of severe GBS infection in newborns born to mother carrying GBS is small, the disease is so severe when it does occur that prevention seems to be the wisest choice, especially as the risk of such treatment to mother and baby is so very small.