Ampicillin is excreted in breast milk in clinically insignificant amounts (Rowe, 2013, Mylonas, 2011, Zhang, 1997, Fulton, 1992, Campbell 1991, Matsuda 1984), much lower than the dose used for newborns and infants ( Chin, 2000; Reali, 2005). No side effects have been observed in infants whose mothers were taking it except for some episodes of diarrhea or candidiasis due to altered intestinal flora (Chin, 2000). The possible negativity of cultures in febrile infants whose mothers take antibiotics should be taken into account, as well as the possibility of gastroenteritis due to altered intestinal flora (Benyamini 2005, Ito 1993, Kafetzis 1981).