What should I do if I have a fever in the first two weeks of pregnancy?

Management of Fever in the First Two Weeks of Pregnancy

If you develop a fever in the first two weeks of pregnancy, immediately take acetaminophen to reduce the fever and seek medical evaluation to determine the cause, as fever during this critical period carries significant risks for miscarriage and fetal malformations. 1, 2

Immediate Actions

Temperature Control

• Take acetaminophen immediately as the only safe antipyretic during pregnancy, which may provide protective effects against fever-related fetal harm 3, 1, 4, 5
• Acetaminophen remains the first-line treatment despite recent epidemiological concerns about neurodevelopmental effects, as these associations are weak and the drug is still considered safe 6
• Do not wait for medical evaluation to start fever reduction—the duration of fever exposure matters 2

Urgent Medical Evaluation Required

• Contact your healthcare provider the same day to determine the underlying cause, as the first trimester carries the highest risk for miscarriage and fetal malformations from fever 1, 2
• Fever in early pregnancy increases risk of neural tube defects by 1.5-3 fold, congenital heart defects, and oral clefts 2

Critical Exposure History Your Provider Will Need

Your healthcare provider must immediately assess specific exposures to guide treatment decisions 1, 4:

• Livestock contact (cattle, sheep, goats)—critical for Q fever risk assessment 4
• Occupational animal exposures 4
• Sick contacts and travel history 1
• Respiratory symptoms requiring chest radiography 1

Diagnostic Workup

Your provider should order 1, 4:

• Complete blood count
• Liver function tests (elevated in up to 85% of Q fever cases) 1
• Q fever serologic testing if any livestock exposure or unexplained fever exists 4
• Chest radiography if respiratory symptoms present 4

Treatment Based on Cause

If Q Fever Cannot Be Excluded

• Trimethoprim-sulfamethoxazole 160mg/800mg twice daily should be started immediately and continued throughout pregnancy if you have any livestock exposure or unexplained fever 1, 4
• This treatment reduces adverse fetal outcomes from 81% to 40% and prevents progression to chronic Q fever 1
• Mandatory folic acid supplementation must accompany this antibiotic to reduce neural tube defect risk 4
• Do not delay treatment waiting for serologic confirmation—start empirically if Q fever cannot be excluded 4

If Common Viral Infection (Most Likely Cause)

• Continue acetaminophen for fever control 3
• Saline nasal irrigation for congestion 3
• Adequate hydration 3
• Antibiotics should NOT be prescribed for viral upper respiratory infections 3

Critical Pitfalls to Avoid

• Never use doxycycline in pregnancy despite being first-line for Q fever in non-pregnant adults, due to effects on fetal bone and teeth 1, 4
• Do not dismiss fever as "just a cold"—the first two weeks (first trimester) carry the highest risk for miscarriage and progression to chronic maternal disease if infection like Q fever is present 1, 4
• Do not delay antibiotic treatment if bacterial infection suspected—untreated first trimester infection most likely results in miscarriage 4

When to Seek Emergency Care

Return immediately or go to emergency department if 3, 4, 5:

• Persistent high fever unresponsive to acetaminophen 4
• Fever worsens or lasts more than 3 days 5
• Severe shortness of breath or difficulty breathing 4
• Development of unilateral facial pain with purulent nasal discharge 3

Follow-Up Monitoring

If Q fever is diagnosed 1, 4:

• Continue trimethoprim-sulfamethoxazole with folic acid throughout pregnancy
• Serologic monitoring at 3,6,12,18, and 24 months postpartum to detect progression to chronic disease
• Close monitoring in all subsequent pregnancies due to risk of recrudescent infection

Understanding the Risks

The evidence shows that fever exposure in early pregnancy substantially increases risk of birth defects, with the strongest evidence for neural tube defects (1.5-3 fold increased risk), congenital heart defects, and oral clefts 2. The combination of first trimester timing and fever creates the perfect storm for adverse outcomes, which is why immediate fever reduction with acetaminophen and prompt medical evaluation are non-negotiable 1, 2.