Improving Intrapartum Group B Streptococcus Prophylaxis in Patients with a Reported Penicillin or Cephalosporin Allergy: A Quality Improvement Project

Published:March 22, 2022DOI:



      To evaluate the impact of a standardized allergy-guided approach to Group B Streptococcus (GBS) prophylaxis in pregnant women with reported penicillin or cephalosporin allergy.


      This interrupted time-series analysis included obstetric patients requiring GBS prophylaxis who reported penicillin or cephalosporin allergies. Patients were divided into baseline (April 1, 2019 to July 21, 2020) and intervention (July 22, 2020 to July 31, 2021) groups. The primary outcome was prophylaxis appropriateness, based on antibiotic type, nature of reaction, and cross-reactivity risk. Secondary outcomes included type of prophylaxis received and antibiotic-related adverse events.


      The study included 88 patients in the baseline period and 52 patients in the intervention period. Appropriate prophylaxis increased from 47% (41/88) to 85% (44/52), with the segmented regression model confirming a statistically significant increase over time (incidence rate ratio 1.57; 95% CI 1.02–2.43, P = 0.04, slope coefficient 1.06/month; 95% CI 1.01–1.10, P = 0.01). Penicillin and cefazolin use increased from 61% (54/88) to 87% (45/52) in the intervention period (P = 0.002), and no hypersensitivity reactions occurred during this period.


      Implementation of standardized allergy-guided prophylaxis safely improved appropriate β-lactam antibiotic use in obstetric patients requiring GBS prophylaxis who reported penicillin and cephalosporin allergies.



      Évaluer les effets d’une démarche normalisée centrée sur les allergies pour la prophylaxie des infections à streptocoque du groupe B (SGB) chez les femmes enceintes réputées allergiques à la pénicilline ou à la céphalosporine.


      Cette analyse de séries chronologiques interrompues concerne des patientes en obstétrique réputées allergiques à la pénicilline ou à la céphalosporine et nécessitant une prophylaxie anti-SGB. Les patientes ont été divisées en deux groupes selon une période de référence (1er avril 2019 au 21 juillet 2020) et une période d’intervention (22 juillet 2020 au 31 juillet 2021). Le critère de jugement principal était la pertinence de la prophylaxie en fonction du type d’antibiotique, de la nature de la réaction et du risque de réactivité croisée. Les critères de jugement secondaires visaient le type de prophylaxie reçue et les événements indésirables liés à l’antibiotique.


      L’étude compte 88 patientes dans la période de référence et 52 dans la période d’intervention. La prophylaxie pertinente a augmenté de 47 % (41/88) à 85 % (44/52), et le modèle de régression segmentée confirme l’augmentation statistiquement significative dans le temps (rapport du taux d’incidence : 1,57; intervalle de confiance [IC] à 95 % : 1,02–2,43, p = 0,04, coefficient de pente : 1,06/mois; IC à 95 % : 1,01–1,10, p = 0,01). L’utilisation de pénicilline ou de céfazoline est passée de 61 % (54/88) à 87 % (45/52) dans la période d’intervention (p = 0,002), et aucune réaction d’hypersensibilité n’est survenue pendant cette période.


      La mise en œuvre d’un protocole normalisé de prophylaxie centrée sur les allergies a amélioré de façon sécuritaire l’utilisation adéquate de l’antibiothérapie aux bêta-lactamines chez les patientes en obstétrique réputées allergiques à la pénicilline ou à la céphalosporine nécessitant une prophylaxie anti-SGB.


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