Comparative Effectiveness of Alternate Antibiotic Therapies for Intrapartum Group B Streptococcus Colonization

Background Intrapartum antibiotic therapy is imperative to minimize maternal-to-fetal transmission of group B Streptococcus (GBS). Penicillin is the gold standard for treatment, but there is a paucity of data on alternate antibiotic therapies for penicillin-allergic patients. This study evaluates the effectiveness of alternate antibiotic therapies in this population. Methods This was a retrospective cohort analysis of GBS-positive pregnant patients at a single safety-net hospital from 2019 through 2022. GBS-positive penicillin-allergic patients were matched 1:2 with nonallergic controls. The primary outcomes were as follows: GBS-positive neonates, neonatal length of stay, GBS septicemia, Apgar scores, fetal demise, and 30-day neonatal complications (sepsis, deafness, pneumonia, or meningitis). χ 2 and Fisher exact analyses were performed on Stata version 16.1 (StataCorp, College Station, TX). Results Two hundred twenty-three GBS-positive pregnant patients were analyzed, including 78 penicillin-allergic (35.0%) and 145 nonallergic (65%). Patients were treated with vancomycin (n = 64, 28.7%), clindamycin (n = 7, 3.1%), cephalosporins (n = 6, 2.7%), or penicillin (n = 146, 65.5%). Rates of GBS-positive infants were low but varied by antibiotic treatment ( P < 0.01): penicillin, 0/146 (0%); vancomycin, 0/64 (0%); clindamycin, 1/7 (14.3%); and cephalosporins, 1/6 (16.7%). There was also a significant difference in 30-day neonatal complications ( P = 0.03): penicillin, 3/146 (2.1%); vancomycin, 0/64 (0%); clindamycin, 1/7 (14.3%); and cephalosporins, 1/6 (16.7%) but no difference in length of stay ( P = 0.07), 5-minute Apgar scores ( P = 0.32), or fetal demise ( P = 1.00). Conclusions Antibiotic effectiveness for GBS-positive pregnant patients varied slightly by medication, but the risk was low in all cohorts. Vancomycin appears to be effective for penicillin-allergic patients, but alternative antibiotic therapies may also provide adequate coverage with a lower risk of promoting antibiotic resistance.