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CME Credit Offered
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Recording available 2/16-5/2
Recording available 2/16-5/2
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AIUM Credit
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Foundation Awardee
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Abstract Award
Abstract Award
Foundation Awardee
Foundation Awardee

Poster Session 2

Category: Clinical Obstetrics

Poster Session 2

(563) Optimal Antibiotic Treatment Strategy for GBS-Negative individuals diagnosed with PPROM prior to 34 Weeks

Wednesday, February 11, 2026
3:30 PM - 5:00 PM  
Objective:
While broad-spectrum antibiotics are known to prolong latency in preterm prelabor rupture of membranes (PPROM( up to 34 weeks of gestation, the necessity of 7 days of penicillin prophylaxis in GBS‑negative individuals remains uncertain. We aimed to determine the association between the two regimens and clinical outcomes, including neonatal outcomes, rate of chorioamnionitis, and duration of latency period

Study Design:
This two‑center retrospective cohort study included all individuals diagnosed with PPROM prior to 34 weeks of gestation and a negative GBS culture between 2018–2024, excluding multiple gestations. Center 1 used the Mercer regimen (2 days IV ampicillin followed by 5 days oral amoxicillin, plus 7 days erythromycin, regardless of GBS status). In contrast, at Center 2, IV ampicillin was given for 2 days and discontinued if the GBS culture was negative, with erythromycin administered identically in both centers.

Results:
The study population included 113 from center 1 and 381 from center 2. Composite neonatal outcome (rates of RDS, TTN, IVH, Neonatal sepsis, Mechanical ventilation and Neonatal death) was more common in center 1 than center 2 (54.9% Vs. 31%, p< 0.001), while the rate of chorioamnionitis was significantly lower in center 1 (2.7% Vs. 10.8%, p=0.013)  Finally, The median latency period was statistically significantly longer in center 1 compared to center 2 although the difference does not seem to have a clinical importance (median: 3,  IQR 2-8 days Vs. median: 3,   IQR 0-10 days p=0.045). The rate of Cesarean section was comparable between the two centers.

Conclusion:

 In the subset of patients with PPROM < 34 weeks of gestation and negative GBS culture, a shorter antibiotics treatment regimen was associated with an increased rate of chorioamnionitis and shorter latency period. In contrast, maternal shorter exposure to antibiotics was associated with improved neonatal outcome. Collectively these data suggest that universal implementation of prolonged broad-spectrum antibiotics requires clinical appraisal.