A patient tests positive for a group B streptococcus (GBS) vaginal infection. She is 35 to 37 weeks’ pregnant and is allergic to penicillin and clindamycin [Cleocin]. What alternative treatment regimen would have the least adverse effect on the fetus? — Yasharn Wang, FNP, Honolulu

Chemoprophylaxis in the intrapartum period for GBS-positive women decreases morbidity and mortality in the neonatal population. Standard treatment of GBS-positive women is either penicillin or ampicillin. If a woman is allergic to penicillin (clarify with her if it is a true anaphylactic reaction), check for sensitivities at the time the GBS culture is obtained and treat according to results.

Treatment options include cefazolin [Ancef] 2 g IV initial dose then 1 g every eight hours (for patients not at high risk of anaphylaxis), clindamycin 900 mg IV every eight hours, erythromycin 500 mg IV every six hours, or vancomycin [Vancocin] 1 g every 12 hours. All of these antibiotics are Pregnancy Category B, with the exception of vancomycin, which is Pregnancy Category C. None of these antibiotics has been shown to have any adverse effects on the fetus. — Mary Newberry, CNM, MSN (167-3)