Do we need to reconsider our antibiotic regimen for preterm premature rupture of membranes (PPROM)? – A retrospective analysis of the current spectrum of pathogens and its relationship with neonatal and maternal outcome

Introduction Although the prophylactic use of antibiotics for preterm premature rupture of membranes (PPROM) is standard practice, the optimal antibiotic regimen remains unclear. According to current guidelines, the standard protocol in our hospital consists of oral administration of amoxicillin for 7 days. Depending on pathogen detection in the vaginal swab, therapy is adjusted. However, in view of the globally changing pathogen spectrum of neonatal sepsis with E. coli as the most common one and its increasing resistance to amoxicillin, the question arises as to whether an adjustment of the antibiotic regimen is necessary.

Methods To determine whether our standard antibiotic regimen is appropriate to cover the current pathogens of neonatal and maternal infection/sepsis, we retrospectively analysed the spectrum of pathogens and its relationship with neonatal and maternal outcome in all deliveries with PPROM in our department from 01/2021 to 12/2022.

Results We included a total of 211 women (54% with PPROM<34+0: group 1 and 46% with PPROM from 34+0 to 36+6: group 2). In group 1, 22% had PPROM<24+0, of which 56% ended in late miscarriage and 8% in neonatal death. In group 1 the median gestational age at PPROM was 31+3 and at birth 33+1, in group 2 both were 35+5.

In group 1 we found neonatal infection in 15%, neonatal sepsis in 5%, histologically confirmed chorioamnionitis in 22% and maternal sepsis in 1%. In group 2, 5% had neonatal infection and there was no case of sepsis. The causative agents of sepsis were 60% E. coli (2/3 resistant to amoxicillin while susceptible to cephalosporins) and 20% each of Enterococcus faecalis and Streptococcus mitis.

In PPROM<34+0, the most common pathogen in the vaginal swab was Ureaplasma urealyticum, E. coli was found in 2%. In the placental swab Staphylococcus epidermidis was most common, E. coli and Ureaplasma were found in 9% each. If the therapy was adapted to the vaginal swab neither Ureaplasma nor E. coli were found in the placental swab.

Discussion Amoxicillin/ampicillin-resistant E. coli is currently the most relevant pathogen in women with PPROM. Particularly in cases<34+0 it is associated with poor neonatal and maternal outcome. Based on the results of our analysis, a switch from our standard antibiotic regimen to cephalosporins and routinely administered azithromycin should be considered. To confirm this data and to evaluate the optimal antibiotic regimen, further research in a prospective setting is planned.

Publication History

Article published online:
15 November 2023