Enterobacteria vaginal colonization among patients with preterm premature rupture of membranes from 24 to 34 weeks of gestation and neonatal infection risk

Aim: Premature rupture of membranes (PROM) increases the neonatal morbidity and mortality, because of its association with a high risk of prematurity and infection. The group B streptococcus (GBS) prophylaxis using amoxicillin doesn't seem to be adapted to the emergence of new bacteria found in vaginal samples (VS). Our study aim was to assess, for PROM occurring at 23-34 weeks' gestation (WG), if the presence of ampicillin-resistant enterobacteria in the vaginal microbiome is predictive of an increased risk of early-onset neonatal infection.

Material and methods: We conducted a prospective, observational, single-center study at the Nice Academic Hospital (level 3 maternity ward), between March 16, 2014 and May 3, 2015, that evaluated patients with preterm PROM (24-34 WG). Two groups were constituted according to the VS bacteria isolates and the amoxycillin-resistant enterobacteria found. Two groups of newborns were constituted depending on the suspicion of perinatal maternal-fetal bacterial infection (MFI). An intent-to-treat analysis was performed.

Results: Among the 67 patients included, 12 newborns presented a strong MFI suspicion, 83% of which were associated to the group of patients with untreated or amoxycillin-resistant enterobacteria VS isolates.

Conclusion: Our study showed that vaginal colonization of untreated or amoxycillin-resistant enterobacteria constitutes a major risk factor of neonatal infection.