What are the recommended postpartum antibiotic regimens for a woman who delivered after chorioamnionitis, for routine cesarean prophylaxis, for postpartum endometritis, and for a cesarean wound infection, including alternatives for severe penicillin allergy?

Postpartum Antibiotic Regimens

After Chorioamnionitis

For women who delivered vaginally after chorioamnionitis, administer only one additional scheduled dose of ampicillin and gentamicin postpartum—this limited course achieves 99% cure rates. 1

Vaginal Delivery

• Continue the intrapartum regimen (ampicillin 2g IV every 6 hours plus gentamicin) with only the next scheduled dose of each antibiotic after delivery 1
• No additional oral antibiotics are needed 2, 1
• This limited approach successfully treats 99% of patients who deliver vaginally 1

Cesarean Delivery

• Add clindamycin 900 mg IV or metronidazole 500 mg IV immediately after umbilical cord clamping 2, 1
• Continue ampicillin and gentamicin for one additional scheduled dose postpartum 1
• Success rate is 85% with this limited course, though obese patients or those with prolonged labor/rupture of membranes may require extended therapy 1
• Treatment failure occurs in approximately 15% of cesarean patients, primarily manifesting as endometritis, wound infection, or septic thrombophlebitis 1

Penicillin Allergy

• For non-severe allergy: substitute cefazolin 2g IV loading dose, then 1g IV every 8 hours for ampicillin 3
• For severe allergy (anaphylaxis, angioedema, urticaria): use clindamycin 900 mg IV every 8 hours plus gentamicin 3
• Approximately 10% of penicillin-allergic patients cross-react with cephalosporins 3

---

Routine Cesarean Prophylaxis

Administer cefazolin 2g IV (3g if weight ≥120 kg) within 60 minutes before skin incision for routine cesarean prophylaxis. 4

Standard Regimen

• Single preoperative dose of cefazolin 2g IV is the standard prophylaxis 4
• No postpartum antibiotics are needed for routine uncomplicated cesarean delivery 2

Severe Penicillin Allergy

• Use clindamycin 900 mg IV plus gentamicin 5 mg/kg IV as a single preoperative dose 5
• Vancomycin 1g IV is an alternative but should be reserved when no other options exist to minimize resistance 5

---

Postpartum Endometritis

Treat postpartum endometritis with IV clindamycin 900 mg every 8 hours plus gentamicin 5 mg/kg every 24 hours—this remains the gold standard regimen. 6

First-Line Treatment

• Clindamycin 900 mg IV every 8 hours plus gentamicin 5 mg/kg IV every 24 hours 6
• Continue IV antibiotics until the patient is afebrile for 24-48 hours 6
• No oral antibiotics are needed after completing IV therapy 6
• This regimen provides excellent coverage for gram-positive anaerobes including Bacteroides fragilis 6

Alternative Regimens

• Extended-spectrum cephalosporins (cefotetan or ceftizoxime) are as effective as cefoxitin 7
• Any alternative must provide similar broad-spectrum coverage, particularly for anaerobes 6

Treatment Failure

• Occurs in approximately 10% of cases 6
• Investigate for wound infection, septic pelvic thrombophlebitis, or abscess 6, 7
• Prolonged fever of undetermined etiology may require extended antibiotic therapy with or without heparin 6

Severe Penicillin Allergy

• The clindamycin-gentamicin regimen is already appropriate for penicillin-allergic patients 6
• If clindamycin resistance is suspected, substitute vancomycin 1g IV every 12 hours for clindamycin 5

---

Cesarean Wound Infection

For cesarean wound infections, open and drain the wound, then treat with clindamycin 900 mg IV every 8 hours plus gentamicin 5 mg/kg IV every 24 hours to cover genital mycoplasmas commonly resistant to penicillins and cephalosporins. 7

Management Approach

• Surgical drainage is essential—open the wound and pack it 7
• Clindamycin 900 mg IV every 8 hours plus gentamicin 5 mg/kg IV every 24 hours provides coverage for genital mycoplasmas (Mycoplasma hominis, Ureaplasma urealyticum) that are commonly isolated from infected cesarean wounds 7
• Genital mycoplasmas are usually resistant to penicillins and cephalosporins, explaining why wound infections are a common cause of treatment failure in patients initially treated with these agents 7

Severe Penicillin Allergy

• The clindamycin-gentamicin regimen is already appropriate 7
• If clindamycin resistance is documented, substitute vancomycin 1g IV every 12 hours 5

Critical Pitfall

• Wound infection surveillance and feedback to surgeons decreases infection rates 7
• Failure to recognize wound infection is a common cause of persistent fever in patients being treated for endometritis 7