Pathogens in preterm prelabour rupture of membranes and erythromycin for antibiotic prophylaxis: a retrospective analysis

Abstract

Introduction: Many authoritative guidelines recommend prescribing erythromycin as antibiotic prophylaxis in patients with preterm prelabour rupture of membranes (PPROM). This study evaluated the spectrum of pathogens in PPROM and assessed the effectiveness of erythromycin prophylaxis.

Methods: This retrospective study enrolled pregnant patients who were diagnosed with PPROM and who delivered at ≥24 weeks of gestation in an obstetric unit from 2013 to 2017. Pathogens isolated from maternal, placental, and neonatal specimens were analysed; their sensitivity profiles to various antibiotics were recorded. Neonatal outcomes were also evaluated.

Results: The overall incidence of PPROM was 2.63%. Gram-positive bacteria were cultured in 18.4% of PPROM patients (most frequent: Group B Streptococcus [GBS; 14.6%]); Gram-negative bacteria were cultured in 12.8% of PPROM patients (most frequent: Escherichia coli [8.0%]). Both Gram-positive and Gram-negative bacteria were significantly associated with early-onset neonatal sepsis (P=0.036 and P=0.001). In analyses stratified by bacterial species, E coli was significantly associated with early-onset neonatal sepsis (P=0.004), whereas GBS was not (P=0.39). Gram-positive bacteria had high rates of resistance to common antibiotics: 42.2% of GBS and 50.0% of Enterococcus and other Streptococcus bacteria were resistant to erythromycin. Escherichia coli had high rates of resistance to ampicillin (70.3%) and gentamicin (33.3%); rates of resistance to co-amoxiclav (3.6%) and intravenous cefuroxime (14.0%) were low.

Conclusion: Gram-positive and Gram-negative bacteria were found in 29.1% of PPROM patients. Administration of erythromycin alone was insufficient to control these bacteria in 67.7% of patients with positive cultures.

Keywords: Erythromycin; Escherichia coli; Fetal membranes, premature rupture; Neonatal sepsis; Streptococcus.