Which antibiotic regimen is indicated for treating suspected chorioamnionitis in the absence of penicillin allergy?

The correct choice for treating suspected chorioamnionitis in the absence of penicillin allergy involves the administration of Ampicillin combined with Gentamicin.

Ampicillin is a broad-spectrum penicillin antibiotic effective against the most common organisms that cause chorioamnionitis, including Group B Streptococcus and other gram-positive bacteria. Gentamicin, an aminoglycoside, effectively covers gram-negative organisms, which is also crucial given that chorioamnionitis may arise from polymicrobial infections, including both aerobic and anaerobic bacteria.

The regimen of Ampicillin 2g IV every 6 hours combined with Gentamicin 5mg/kg IV once daily provides a comprehensive approach to treat the infection, targeting both gram-positive and gram-negative organisms. This combination is well-supported by guidelines and clinical protocols for managing chorioamnionitis.

In contrast to other options, the remaining antibiotic regimens either lack the necessary broad-spectrum coverage needed for suspected chorioamnionitis or do not align with established treatment guidelines.