Preterm prelabor rupture of membranes: the use of amniocentesis to detect intraamniotic infection reduces maternal and neonatal duration of antibiotic exposure

Abstract

Background: Current management guidelines for patients with preterm prelabor rupture of membranes at <32+0 weeks of gestation recommend administering antibiotics, although evidence on their benefits for short- and long-term neonatal outcomes is poor.

Objective: This study aimed to evaluate whether the use of amniocentesis to detect intraamniotic infection reduces maternal and neonatal duration of antibiotic exposure.

Study design: This was a retrospective observational cohort study (2014-2023) including patients diagnosed with preterm prelabor rupture of membranes at <32+0 weeks of gestation who underwent amniocentesis at admission to assess the presence of intraamniotic infection. We compared 2 groups according to antenatal antibiotic management. From 2014 to 2019, patients received at least 5 days of broad-spectrum antibiotic treatment (including intravenous ampicillin and gentamicin and a single dose of oral azithromycin), regardless of intraamniotic infection status (standard management group). Beyond 2019, gentamicin was substituted for intravenous ceftriaxone and azithromycin for oral clarithromycin. Antibiotic treatment duration was optimized on the basis of amniotic fluid analysis (amniocentesis-based management): if amniotic fluid glucose concentrations were ≥14 mg/dL and Gram staining did not show the presence of bacteria, antibiotic treatment was discontinued at 48 hours. Otherwise, antibiotic therapy was prolonged at least until microbiological amniotic fluid results. Regardless of the management group, if intraamniotic infection was diagnosed, the type of antibiotic was individualized according to the bacteria isolated, and treatment was prolonged for 7 to 10 days unless delivery occurred earlier. There were no other differences in maternal management between the 2 periods.

Results: A total of 172 patients diagnosed with preterm prelabor rupture of membranes at <32+0 weeks of gestation were included (122 in the standard management group and 50 in the amniocentesis-based management group). The prevalence of intraamniotic infection was 29% in both periods, with most cases (61%) being due to Ureaplasma species. There were no differences in maternal characteristics between the 2 groups. As expected, in the amniocentesis-based management group, maternal exposure to antibiotics was shorter (median [25th centile-75th centile] of 2 [2-3] days [amniocentesis-based management] vs 5 days [4-5] [standard management]; P<.0001). In line with the reduction of the duration of antibiotic therapy, we observed that maternal hospital stay was significantly shorter (5 [4-9] vs 11 [5-21] days; P=.001) and outpatient management was more frequent (68% vs 47%; P=.011) in the amniocentesis-based management group. No differences were observed in maternal morbidity. Similar results were found when neonatal outcomes were evaluated. In the amniocentesis-based management group, neonates received less antibiotic treatment at admission (odds ratio [95% confidence interval], 0.31 [0.15-0.61]; P<.001) and had less exposure to antibiotics during hospitalization (6±14 vs 13±18 days in the standard management group; P=.023). This did not translate into worse neonatal outcomes.

Conclusion: Management of preterm prelabor rupture of membranes based on amniotic fluid analysis was associated with shorter maternal and neonatal antibiotic exposure and shorter maternal length of hospitalization, and allowed outpatient management without jeopardizing maternal or neonatal outcomes.

Keywords: Ureaplasma; amniocentesis; amniotic fluid; antibiotics; bacteria; chorioamnionitis; intraamniotic infection; neonatal and maternal outcomes; prelabor rupture of membranes; preterm; preterm prelabor rupture of membranes.