Ped doc here. Group B strep can cause severe sepsis in neonates and I would definitely recommend that she get 1-2 doses of an antibiotic while in labor. I have not seen any good evidence that this sort of treatment causes any problems down the road for the baby. Furthermore, if you consider the mechanism that this paper suggests, it involves the manipulation of gut flora. A neonate&#x27;s GI tract is sterile when it comes into the world, and is colonized over the first months to years of life. So since there are no bacteria to affect, this proposed mechanism should have no relevance. Also, Amp&#x27;s half-life is just a few hours so no long-lasting presence in your baby. Don&#x27;t mess with group B strep--before we understood how to deal with it, it made a lot of babies very sick and many died.