Alternative antimicrobials for prophylaxis of the Group B Streptococcus maternal-fetal disease.

Introduction: GBS colonization is an important risk factor for maternal and neonatal infection morbidity and mortality. Intrapartum antibiotics may prevent vertical transmission of GBS from colonized mothers to their babies. The objective of this study was to evaluate the effectiveness of cefazolin prophylactic regimen for GBS disease, comparing it to the established penicillin-based protocols, given the opportunity provided by the temporary unavailability of first-choice antibiotics in Brazil.

Methodology: A retrospective analysis was conducted at the Hospital Femina Obstetrics Service between January and December 2015. Ninety-eight pregnant women received standard penicillin (70 patients) or ampicillin (28 patients) antibiotic prophylaxis, and 251 pregnant women received an alternative prophylaxis with cefazolin during the study period. Risk factor, Maternal and neonatal outcomes were evaluated and compared between groups.

Results: No significant difference was found in maternal (RR = 0.71; IC 95%:0.30-1.68; p = 0.709) and neonatal (RR = 0.84; IC 95%:0.61-1.15; p = 0.271) outcomes between those patients using the alternative antibiotic prophylaxis in comparison to the standard antibiotics, with the dependent variable of maternal and neonatal outcomes grouped and controlled for potential confounding variables.

Conclusions: The antibiotics used as alternatives to penicillin and ampicillin for the prevention of maternal-fetal GBS disease are poorly studied, and this study indicate that cefazolin can be an optimal choice, offering safety in the use of this antibiotic in situations where penicillins are contraindicated or unavailable.