Antibiotic choice for Group B Streptococcus prophylaxis in mothers with documented penicillin allergies and associated newborn outcomes

ObjectiveTo evaluate intrapartum Group B Streptococcus (GBS) prophylaxis in women with documented penicillin allergy compared to women without penicillin allergy, and to investigate associated differences in neonatal outcomes. Study DesignThis retrospective cohort study included GBS positive pregnant women who had a vaginal delivery or cesarean section after trial of labor at >35 weeks of gestation at a high-volume urban hospital (2005-2018). Management of women who reported penicillin allergy was compared to women without a reported penicillin allergy. Maternal outcome was type of antibiotic administered for GBS prophylaxis (beta-lactam antibiotic prophylaxis defined as administration of penicillin, ampicillin, or cefazolin; alternative antibiotic prophylaxis defined as vancomycin or clindamycin). Neonatal outcomes included number of blood draws, antibiotic administration, neonatal intensive care unit (NICU) admission, and length of stay. Univariate analyses were performed. ResultsOf the 11,334 mother-neonate pairs meeting eligibility criteria, 1170 (10.3%) women had a documented penicillin allergy, and of these women 51 (4.4%) had a co-existing cephalosporin allergy. Among women with a reported penicillin allergy (n=1170), 49 (4.2%) received penicillin or ampicillin, 259 (22.1%) received cefazolin, 449 (38.4%) received clindamycin and 413 (35.3%) received vancomycin. Women with documented penicillin allergy were significantly more likely to receive alternative GBS prophylaxis compared to women without penicillin allergy (73.7% vs. 0.2%, p<0.01). Neonates of women who received alternative GBS prophylaxis had more lab draws compared to neonates of women who received beta-lactam antibiotic agents (20.8% vs. 17.3%, p<0.01). ConclusionPregnant women with documented penicillin allergy received alternative antibiotics for GBS prophylaxis at a significantly higher frequency than women without a penicillin allergy. This was associated with an increased frequency of blood draws among neonates of mothers with penicillin allergy.