First-Line Antibiotic Treatment for Mastitis in Pregnancy
For pregnant women with mastitis, initiate treatment with dicloxacillin or cephalexin as first-line antibiotics targeting Staphylococcus aureus, as these agents are safe in pregnancy and effective against the most common causative organism. 1, 2
Initial Conservative Management (1-2 Days)
Before starting antibiotics, attempt conservative measures for 24-48 hours unless systemic symptoms are severe:
- Continue breastfeeding or milk expression regularly - this is essential for treatment and should never be discontinued 3, 4, 5
- Use NSAIDs for pain control and apply ice to the affected breast 5
- Feed the infant directly from the breast rather than pumping, as pumping may worsen inflammation 5
- Avoid aggressive breast massage, heat application, and excessive pumping - these increase tissue trauma and milk overstimulation, worsening mastitis 5
Antibiotic Therapy
If symptoms fail to improve after 1-2 days of conservative management, or if systemic symptoms (fever, chills) are present initially:
Preferred First-Line Agents in Pregnancy:
- Dicloxacillin - targets Staphylococcus aureus and Streptococcus species, with minimal milk transfer (RID 0.03%) 2, 6
- Cephalexin - safe in pregnancy with no adverse effects reported in non-HS pregnant patients 1, 2
- Clindamycin - moderate evidence supports safety in pregnancy, though combination therapy data are limited 1
- Azithromycin - safe in pregnancy based on studies in non-HS patients 1
Important Safety Considerations:
The American Academy of Pediatrics and CDC endorse these antibiotics as safe during pregnancy, with no documented teratogenic effects 1, 2. All allow continued breastfeeding, as drug concentrations in milk do not produce toxicity in nursing infants 1.
When to Escalate Care
Hospitalize if:
- Fever and chills persist despite outpatient antibiotics, indicating systemic involvement 3
- Concern for sepsis develops 3, 5
- Symptoms worsen or recur despite treatment 5
During hospitalization:
- Provide IV antibiotics if oral therapy fails 5
- Ensure access to breast pump if mother-infant separation occurs 3
- Maintain pain management with appropriate analgesics 3
- Provide trained lactation support staff 3, 4
Management of Complications
If breast abscess develops (occurs in ~10% of cases):
- Perform ultrasound-guided needle aspiration as the preferred drainage method 4
- Continue breastfeeding on the affected side, provided the infant's mouth does not contact purulent drainage 3, 4, 2
- Surgical drainage may be required if needle aspiration fails 2
Critical Pitfalls to Avoid
- Never discontinue breastfeeding - this worsens mastitis and increases abscess risk 3, 4
- Avoid overstimulation - excessive pumping, heat, and aggressive massage exacerbate inflammation 5
- Do not delay treatment - untreated mastitis progresses to abscess formation 3
- Avoid doxycycline, metronidazole, and TMP-SMX in pregnancy due to potential risks 1