Antibiotics in Pregnancy

Practical, bedside-friendly regimens (adults) with pregnancy safety notes, penicillin-allergy pathways, pneumonia (CAP/HAP) quick regimens, postpartum prophylaxis considerations (esp. IAI/chorio), and DailyMed labeling links. Doses may require renal adjustment and clinical judgment.
UPDATED 12/27/2025
FOR MEDICAL PROFESSIONAL USE ONLY This page is an educational quick-reference. Confirm diagnosis, gestational age considerations, allergy type, renal/hepatic function, QT risk, drug interactions, and local antibiograms. Consult product labeling (DailyMed) and current institutional protocols.
Penicillin allergy approach Common outpatient infections Pneumonia (CAP/HAP) PPROM latency Chorioamnionitis / IAI Postpartum prophylaxis (risk-based) MRSA DailyMed links References

Penicillin allergy: quick approach

Choose alternatives based on reaction type (low-risk vs immediate hypersensitivity/anaphylaxis).

Tip Document reaction (hives? angioedema? anaphylaxis? severe rash/SJS?) and timing. Many patients labeled “penicillin allergic” tolerate cephalosporins; avoid cephalosporins when there is immediate-type hypersensitivity.

  • Non–immediate / low-risk history (e.g., GI upset, vague childhood rash): cephalosporins are often acceptable.
  • Immediate-type hypersensitivity (urticaria, angioedema, bronchospasm, hypotension): avoid penicillins and usually avoid cephalosporins; use macrolide or clindamycin when appropriate; consider specialist input for serious infections.
  • Severe cutaneous reactions (SJS/TEN, DRESS): avoid β-lactams; use non–β-lactam alternatives only.
GBS & obstetric infections: When β-lactam allergy is present, intrapartum prophylaxis and latency/IAI regimens may require GBS-directed coverage and/or susceptibility data per institutional protocol.

Medication safety highlights

Common pregnancy “avoid / caution” items frequently encountered in outpatient care.
  • Tetracyclines (e.g., doxycycline): generally avoid (fetal teeth/bone effects).
  • Fluoroquinolones (e.g., levofloxacin, ciprofloxacin): generally avoid unless no alternatives.
  • TMP-SMX: avoid 1st trimester when possible (folate antagonism) and avoid near term when possible (neonatal hyperbilirubinemia risk); consider folate supplementation if used.
  • Nitrofurantoin: commonly used for cystitis; generally avoid near term (38–42 w) and in G6PD deficiency.
  • Clarithromycin: generally avoid in pregnancy (alternative macrolides preferred).

Use the narrowest effective agent and shortest effective duration. Reassess quickly if not improving.

UTI spectrum in pregnancy

Common dosing examples for adult patients. Tailor to culture/susceptibilities, renal function, and local resistance patterns.
Asymptomatic bacteriuria / acute cystitis (lower UTI)

Typical options Choose based on culture, allergies, and local resistance. Avoid nitrofurantoin near term and in known G6PD deficiency.

  • Cephalexin 500 mg PO q6h for 5–7 days
  • Amoxicillin 500 mg PO q8h or 875 mg q12h for 5–7 days (use if susceptible; resistance is common in some regions)
  • Amoxicillin-clavulanate 500 mg PO q8h or 875 mg q12h for 5–7 days (use if susceptible; resistance is common in some regions)
  • Nitrofurantoin 100 mg PO q12h for 5–7 days (avoid near delivery; avoid if G6PD deficiency)
  • Sulfamethoxazole-trimethoprim 800/160 mg PO q12h for 5–7 days (avoid 1st trimester and near delivery when possible)
  • Fosfomycin 3 g PO once (single-dose cystitis option)
DailyMed: cephalexin DailyMed: amoxicillin DailyMed: nitrofurantoin DailyMed: fosfomycin
Pyelonephritis (inpatient)

Inpatient Treat as a potentially severe infection in pregnancy. Start IV therapy, adjust to cultures, and transition to oral therapy when clinically improved.

  • Ceftriaxone 1 g IV q24h (commonly used empiric option)
  • Ampicillin 2 g IV q6h + gentamicin 1.5 mg/kg IV q8h OR 5 mg/kg q24h (institution-dependent; renal adjust)
  • Cefepime 1 g IV q12h
  • Aztreonam 1 g IV q8–12h (β-lactam allergy option; ensure adequate coverage for likely pathogens)
  • Total duration: commonly ~14 days (IV → PO step-down when improved)
DailyMed: ceftriaxone DailyMed: ampicillin DailyMed: gentamicin ACOG: UTI in pregnancy (2023)

Common outpatient infections (pregnancy)

Typical adult regimens formatted for fast scanning. Confirm diagnosis and local resistance.
Pharyngitis (Group A Strep suspected/confirmed)

First-line Penicillin V or amoxicillin are standard options when GAS is confirmed or strongly suspected.

Scenario Preferred Penicillin allergy alternatives Notes
GAS pharyngitis (adult) Penicillin V 500 mg PO BID × 10 days
OR Amoxicillin 500 mg PO BID × 10 days		 Non-immediate allergy: cephalexin 500 mg PO BID × 10 days
Immediate allergy: azithromycin 500 mg day 1 then 250 mg daily days 2–5 or clindamycin 300 mg PO TID × 10 days 		Macrolide/clindamycin resistance varies; use testing and local data.
DailyMed: amoxicillin DailyMed: penicillin V DailyMed: cephalexin DailyMed: azithromycin DailyMed: clindamycin
Acute bacterial rhinosinusitis (sinusitis)

First-line Amoxicillin-clavulanate is commonly recommended for empiric therapy in adults when ABRS criteria are met. Pregnancy note Some nonpregnancy alternatives (doxycycline, fluoroquinolones) are generally avoided in pregnancy.

Scenario Preferred Penicillin allergy alternatives (pregnancy-focused) Duration
Uncomplicated ABRS (adult) Amoxicillin-clavulanate 875/125 mg PO BID Non-immediate allergy: cefpodoxime 200 mg PO BID or cefuroxime 500 mg PO BID (institution-dependent)
Immediate allergy: consider specialist input; if antibiotic needed and no β-lactams usable, options may be limited—balance resistance concerns and individual risk. 		Typically 5–7 days if improving

Supportive care: saline irrigation; consider intranasal corticosteroid if allergic rhinitis. Reassess if worsening after 48–72h or not improving after 3–5 days.

DailyMed: amoxicillin-clavulanate DailyMed: cefpodoxime DailyMed: cefuroxime
Otitis media (adult)

First-line Amoxicillin is commonly used; amoxicillin-clavulanate is often chosen if recent β-lactam exposure, severe disease, or concern for β-lactamase producers.

Scenario Preferred Penicillin allergy alternatives Duration
Acute otitis media (adult) Amoxicillin 1000 mg PO TID
or Amoxicillin-clavulanate 875/125 mg PO BID
Expect symptom improvement within ~48–72 hours; reassess if not improving. 		Non-immediate allergy: cefdinir 300 mg PO BID or cefpodoxime 200 mg PO BID
Immediate allergy: azithromycin (local resistance may limit usefulness) 		5–10 days (severity-dependent)
DailyMed: amoxicillin DailyMed: amoxicillin-clavulanate DailyMed: cefdinir DailyMed: azithromycin
Infected tooth / odontogenic cellulitis

Key point Definitive dental treatment (drainage, extraction, etc.) is primary; antibiotics are generally reserved for systemic involvement, spreading cellulitis, or immunocompromise.

Scenario Preferred Penicillin allergy alternatives Notes
Odontogenic infection / cellulitis
Admit if airway risk (e.g., Ludwig’s angina), deep space infection, systemic toxicity.		 Amoxicillin 500 mg PO TID
or Amoxicillin-clavulanate 875/125 mg PO BID 		Non-immediate allergy: cephalexin 500 mg PO QID
Immediate allergy: azithromycin (e.g., 500 mg day 1 then 250 mg daily days 2–5) or clindamycin 300 mg PO QID 		Reevaluate within ~48–72h; stop ~24h after symptom resolution when appropriate and source control achieved.
DailyMed: amoxicillin-clavulanate DailyMed: cephalexin DailyMed: clindamycin DailyMed: azithromycin
MRSA (skin/soft tissue infections)

Practical Incision & drainage is primary for abscesses. Add antibiotics when systemic illness, rapid progression, significant cellulitis, immunocompromise, or failed initial therapy.

Setting Common oral options (if susceptible) Pregnancy notes Severe infection
Outpatient SSTI w/ MRSA concern Clindamycin
TMP-SMX (SMX-TMP)
Linezolid (select cases) 		Avoid tetracyclines (e.g., doxycycline). TMP-SMX: avoid 1st trimester when possible and avoid near term when possible. Consider GAS coverage if cellulitis is prominent. Vancomycin IV (or equivalent MRSA agent) per severity/setting
DailyMed: clindamycin DailyMed: TMP-SMX DailyMed: linezolid DailyMed: vancomycin

Pneumonia in pregnancy

Community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP): pregnancy-friendly empiric frameworks. Use local pathways/antibiograms; consider ID consult for severe disease.
Clinical priorities Evaluate severity (vitals, oxygenation, imaging), influenza/COVID when appropriate, aspiration risk, and comorbidities. Maintain maternal oxygenation (fetal oxygen delivery depends on maternal PaO2).
Community-acquired pneumonia (CAP) — empiric pregnancy-focused options

Coverage goal Typical CAP pathogens + “atypicals.” Avoid doxycycline, clarithromycin, and fluoroquinolones when possible in pregnancy.

Setting Common pregnancy-compatible empiric options β-lactam allergy considerations Notes
Outpatient, mild Amoxicillin 1 g PO TID + azithromycin (500 mg day 1 then 250 mg daily days 2–5)
Alternative in select low-risk settings: azithromycin alone (local resistance dependent) 		Immediate β-lactam allergy: azithromycin may be used; if severe disease or concern for DRSP, consider specialist input (options can be limited). If comorbidities or recent antibiotics/DRSP risk: prefer β-lactam + macrolide combination.
Outpatient w/ comorbidities or DRSP risk Amoxicillin-clavulanate 875/125 mg PO BID + azithromycin
or cefpodoxime 200 mg PO BID + azithromycin
or cefuroxime 500 mg PO BID + azithromycin 		Immediate β-lactam allergy: consider ID/pulmonary input; weigh maternal benefit vs limited pregnancy-compatible alternatives. Reassess at 48–72h; ensure follow-up and safety-net.
Inpatient (non-ICU) Ceftriaxone 1–2 g IV q24h + azithromycin 500 mg IV/PO daily
or cefotaxime + azithromycin (institution-dependent) 		Immediate β-lactam allergy: aztreonam + azithromycin (verify coverage suitability); consider ID. Switch to PO when clinically stable; typical minimum total duration ≥5 days once stable (guideline-based).
ICU/severe CAP (no pseudomonal risk) Ceftriaxone (or cefotaxime) + azithromycin Immediate β-lactam allergy: specialist-guided regimen Avoid monotherapy in severe CAP.
Severe CAP w/ pseudomonal risk factors Cefepime or piperacillin-tazobactam or meropenem + azithromycin
+/- aminoglycoside only if strong indication (fetal ototoxicity risk) 		High-complexity: manage with ID/critical care Pseudomonal risk examples: bronchiectasis, cystic fibrosis, prolonged corticosteroids.
DailyMed: amoxicillin DailyMed: amoxicillin-clavulanate DailyMed: azithromycin DailyMed: ceftriaxone Pregnancy CAP review (table of empiric options) ATS/IDSA CAP guideline (2019)
Hospital-acquired pneumonia (HAP) — empiric framework (pregnancy)

Definition HAP = pneumonia developing ≥48 hours after hospital admission (not present at admission). Empiric choices depend on local resistance, recent antibiotics, and MRSA/Pseudomonas risk.

Risk features (examples) Empiric approach (examples) Pregnancy notes De-escalation
Lower MDR risk
No recent IV antibiotics; stable; low local resistance 		One anti-pseudomonal β-lactam (choose per local pathway):
piperacillin-tazobactam or cefepime or meropenem 		Prefer β-lactams over fluoroquinolones when feasible in pregnancy. Narrow promptly to culture/PCR results.
MRSA risk (examples)
Prior MRSA colonization/infection, high local prevalence, severe illness 		Above + add vancomycin or linezolid Use MRSA coverage only when risk is meaningful; linezolid has limited pregnancy experience. Stop MRSA agent if MRSA not supported by testing.
Higher risk for resistant gram-negatives / Pseudomonas
Recent IV antibiotics; structural lung disease; ICU-level severity (institution-specific) 		Institution-guided broad regimen; may require dual anti-pseudomonal coverage in select high-risk settings (avoid duplicate β-lactams).
Complex: manage with ID/critical care. 		Aminoglycosides generally avoided unless strong indication. Balance maternal benefit vs fetal risks. Culture-guided de-escalation is essential.
IDSA/ATS HAP/VAP guideline (2016) HAP/VAP guideline (PubMed) DailyMed: piperacillin-tazobactam DailyMed: cefepime DailyMed: vancomycin DailyMed: linezolid

PPROM latency antibiotics

Typical NICHD/MFMU regimen (7 days total). Avoid amoxicillin-clavulanate for latency.

Standard regimen IV ampicillin 2 g q6h + IV erythromycin 250 mg q6h × 48h → then PO amoxicillin 250 mg q8h + PO erythromycin base 333 mg q8h × 5 days (7 days total).

  • Azithromycin (e.g., 1 g single dose) is often used to replace erythromycin if unavailable or poorly tolerated.
  • Amoxicillin-clavulanate is not recommended for latency (NEC signal in some data).
  • β-lactam allergy: individualize based on allergy severity and GBS considerations; follow institutional pathway.
Penicillin allergy alternatives for PPROM latency (examples)

Examples only — local protocols and GBS considerations may differ.

  • Low risk Low risk for anaphylaxis/angioedema/respiratory distress/urticaria:
    Cefazolin 1 g IV q8h + IV erythromycin 250 mg q6h × 48h → then PO cephalexin 500 mg q6h + PO erythromycin base 333 mg q8h × 5 days (7 days total).
  • High risk High risk for anaphylaxis/angioedema/respiratory distress/urticaria:
    Clindamycin 900 mg IV q8h + gentamicin 5 mg/kg IV q24h + IV erythromycin 250 mg q6h × 48h → then Clindamycin 300 mg PO q8h + PO erythromycin base 333 mg q8h × 5 days (7 days total).
  • Do not use clindamycin alone for latency; ensure appropriate spectrum per protocol.
  • Use vancomycin when GBS is positive/unknown and clindamycin resistance is present or susceptibility is unknown, per institutional protocol.
DailyMed: ampicillin DailyMed: erythromycin DailyMed: amoxicillin DailyMed: azithromycin DailyMed: cefazolin DailyMed: cephalexin DailyMed: clindamycin DailyMed: gentamicin

Alternative (UK practice in some settings): erythromycin 250 mg PO QID up to 10 days or until labor if earlier.

Chorioamnionitis / intra-amniotic infection (IAI)

Common intrapartum regimens; add cesarean anaerobic coverage when indicated. Postpartum antibiotics are often not needed beyond one additional dose in immune-competent patients unless ongoing fever/instability.
Intrapartum treatment regimens (examples)

Common first-line Ampicillin + gentamicin intrapartum; if cesarean, add anaerobic coverage (e.g., clindamycin) at cord clamp.

Scenario Regimen Penicillin allergy options Notes
IAI / chorioamnionitis (vaginal delivery anticipated) Ampicillin 2 g IV q6h + gentamicin
(institution dosing: 1.5 mg/kg q8h or 5 mg/kg q24h; renal adjust)		 Non-immediate allergy: cefazolin + gentamicin (institution-dependent)
Immediate allergy: clindamycin + gentamicin or vancomycin + gentamicin 		Confirm local dosing conventions; renal dosing for gentamicin.
IAI with cesarean delivery Above + add clindamycin 900 mg IV once at cord clamp (or metronidazole 500 mg IV once per protocol) As above (ensure anaerobic coverage) Evidence supports none or one additional postpartum dose for many immune-competent patients; extend if persistent fever/instability.
Alternative (some institutions) Ampicillin-sulbactam 3 g IV q6h (monotherapy) Depends on allergy type Institution-specific; consider resistance patterns.
DailyMed: gentamicin DailyMed: ampicillin DailyMed: clindamycin DailyMed: vancomycin DailyMed: ampicillin-sulbactam ACOG CO 712 (IAI) Evidence review (Conde-Agudelo 2020)

Postpartum antibiotic prophylaxis — expanded risk-based strategy

Focus: cesarean delivery and deliveries complicated by IAI/chorio. Separate “prophylaxis” from treatment of established infection.
Baseline: cesarean prophylaxis (pre-incision) — common U.S. approach
  • Cefazolin IV pre-incision (weight-based per institution; commonly 2 g, or 3 g if high maternal weight).
  • Nonelective cesarean (in labor and/or ruptured membranes): add azithromycin 500 mg IV once (adjunctive extended-spectrum prophylaxis), unless contraindicated.
  • Severe immediate β-lactam allergy: often clindamycin 900 mg IV + gentamicin 5 mg/kg IV (institution-dependent).
  • Known MRSA colonization / high MRSA risk: some pathways add vancomycin (timing and dosing per institution).
C/SOAP trial (Tita 2016, NEJM) ACOG PB 199 (Prophylactic antibiotics) DailyMed: cefazolin DailyMed: azithromycin DailyMed: clindamycin DailyMed: gentamicin
After delivery with IAI/chorio: postpartum antibiotics (risk-based)

Guideline baseline If treated intrapartum, many immune-competent patients need no postpartum antibiotics after vaginal delivery, and one additional postpartum dose is often adequate after cesarean (ensure anaerobic coverage). Extend therapy when ongoing fever, unstable vitals, bacteremia, or other high-risk features are present.

Risk tier (practical) Examples Suggested postpartum approach (examples) Notes
Tier 0
Vaginal delivery		 IAI treated intrapartum; clinically improving; afebrile after delivery No postpartum antibiotics
or consider one additional dose per local pathway 		Evidence reviews and ACOG guidance support minimizing postpartum antibiotics in many cases.
Tier 1
Cesarean, low complication burden		 IAI treated intrapartum; hemodynamically stable; no persistent fever One additional postpartum dose of the chosen regimen
Ensure anaerobic coverage (e.g., clindamycin or metronidazole component). 		Supported by trials showing low failure rates with a single additional dose in immune-competent patients.
Tier 2
Cesarean + higher risk of endometritis		 Persistent intrapartum fever near delivery; prolonged labor/ROM; significant postpartum uterine tenderness; difficult surgery/EBL; clinician concern for higher infectious risk Extended postpartum prophylaxis (institutional strategy): e.g., continue broad-spectrum regimen for ~24 hours postpartum if clinically stable, then stop. An AJOG pre/post intervention by Ishino et al reported that a standardized risk-based extended postpartum prophylaxis strategy (including a 24-hour prophylaxis approach after cesarean in IAI cases) was associated with reduced postpartum endometritis; implement only within institutional stewardship frameworks.
Tier 3
Treat as infection (not prophylaxis)		 Ongoing fever postpartum; unstable vitals; bacteremia; concern for endometritis/sepsis Therapeutic treatment per endometritis/sepsis protocols (not prophylaxis); ID consult recommended Do not “under-treat” postpartum sepsis. Escalate and obtain cultures/imaging as indicated.
ACOG CO 712 (IAI) Conde-Agudelo 2020 evidence review Edwards 2003 trial (one additional dose postpartum) Ishino et al. AJOG 2022 (risk-based extended prophylaxis) — journal page

Note: Some journal full-text pages may be access-restricted; use institutional access for exact protocol details and outcomes.

Other postpartum procedures where single-dose prophylaxis is commonly considered

Example Uterine exploration/instrumentation increases endometritis risk; some reviews recommend single-dose combination prophylaxis.

  • Manual placenta removal: single-dose ampicillin 2 g IV (or cefazolin 1 g IV) + metronidazole 500 mg IV (example recommendation)
  • D&C / manual vacuum aspiration / intrauterine balloon tamponade: single-dose ampicillin 2 g IV + metronidazole 500 mg IV (example recommendation)
Lambert et al. 2023 (recommendations after uterine exploration/instrumentation) DailyMed: metronidazole DailyMed: cefazolin

DailyMed labeling links (quick list)

Search links to manufacturer package inserts and labeling on DailyMed (NLM).
cephalexin cefazolin ceftriaxone cefepime piperacillin-tazobactam metronidazole nitrofurantoin fosfomycin azithromycin erythromycin amoxicillin-clavulanate TMP-SMX linezolid vancomycin

Tip: use DailyMed for exact strengths, formulations, contraindications, renal/hepatic adjustments, and boxed warnings where applicable.

Show / hide references
  1. ACOG Practice Bulletin: Use of Prophylactic Antibiotics in Labor and Delivery.
  2. ACOG Committee Opinion No. 712: Intrapartum Management of Intraamniotic Infection.
  3. Conde-Agudelo A, et al. Management of Clinical Chorioamnionitis: An Evidence-Based Approach. (Review; postpartum antibiotics often unnecessary; if given, support for a single additional dose.)
  4. Edwards RK, et al. Single additional dose postpartum therapy for women with chorioamnionitis. (Trial supporting one additional postpartum dose in immune-competent women.)
  5. Ishino A, et al. Expanded Risk-Based Strategy for Postpartum Antibiotic Prophylaxis in Deliveries Complicated by Intraamniotic Infection. Am J Obstet Gynecol. 2022. (Journal access may be restricted; protocol/outcomes via institutional access.)
  6. Tita ATN, et al. Adjunctive Azithromycin Prophylaxis for Cesarean Delivery. NEJM. 2016.
  7. Lambert KA, et al. Antibiotic Recommendations After Postpartum Uterine Exploration or Instrumentation. 2023.
  8. Metlay JP, et al. ATS/IDSA Community-Acquired Pneumonia Guideline. 2019.
  9. Kalil AC, et al. IDSA/ATS Hospital-acquired and Ventilator-associated Pneumonia Guidelines. 2016.
  10. “Pneumonia in the Pregnant Patient” (review): PMC full text. (Includes pregnancy-focused empiric CAP options table.)
  11. Lin LL, et al. Efficacy of prophylactic antibiotics for PPROM: systematic review and network meta-analysis. Am J Obstet Gynecol MFM. 2023;5(7):100978. PMID: 37094635.
  12. IDSA SSTI guideline (MRSA-active agents): Clinical Infectious Diseases (2014).
  13. DailyMed (NLM): dailymed.nlm.nih.gov.

This page intentionally does not replace institution-specific pathways (e.g., PPROM/IAI protocols, pneumonia stewardship bundles, local antibiograms).