What is the recommended dose of paracetamol (acetaminophen) for pregnant women?

Paracetamol Dosing in Pregnancy

Pregnant women should use paracetamol at 650-975 mg every 6-8 hours (maximum 4 g daily), only when medically necessary, at the lowest effective dose for the shortest possible duration—ideally ≤7 days. 1, 2

Standard Dosing Regimens

• For general pain or fever during pregnancy: Use 650 mg every 6 hours or 975 mg every 8 hours as needed 1
• Maximum daily dose: Do not exceed 4 g (4000 mg) per day to prevent severe liver injury 1
• For chronic use: Consider limiting to 3 g or less per day due to hepatotoxicity concerns 1

Critical Safety Principles

Paracetamol is the first-line analgesic throughout all trimesters of pregnancy because it does not cause premature ductus arteriosus closure or oligohydramnios, unlike NSAIDs. 1, 2 The American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine, and European Society of Cardiology all recommend it as the safest option when pain or fever medication is medically indicated. 1, 2

However, use only when medically necessary—not routinely or prophylactically. 2

Duration Matters More Than Single Doses

• Short-term use (≤7 days) appears safer based on current evidence 1
• Prolonged use (>28 days) or second/third trimester chronic exposure is associated with 20-30% increased risk of ADHD and autism spectrum conditions in offspring 1, 2
• If use extends beyond a few days, reassess necessity and monitor closely 1, 2

Specific Clinical Scenarios

Post-Vaginal Delivery

• Use 650 mg every 6 hours OR 975 mg every 8 hours as part of multimodal analgesia 1

Post-Cesarean Delivery

• Use 975 mg every 8 hours as standing medication 1, 2

Migraine During Pregnancy

• Paracetamol is first-line despite relatively poor efficacy (alternatives carry greater risks) 1

Important Caveats and Pitfalls

• Avoid combination products containing paracetamol (e.g., oral decongestants + paracetamol in first trimester increase risk of gastroschisis and intestinal atresia) 1
• Check all medications the patient is taking to prevent accidental overdose from multiple paracetamol-containing products 1
• NSAIDs are contraindicated after 28 weeks gestation (and generally avoided in first trimester), making paracetamol the only safe oral analgesic option in late pregnancy 1
• NSAIDs may be considered ONLY during second trimester (weeks 14-27) if absolutely necessary 1

When to Escalate

• Severe pain not responding to paracetamol warrants medical evaluation to identify underlying causes 1
• For severe pain uncontrolled by paracetamol alone, consider short-acting opioids at lowest effective dose for shortest duration, though these carry significant risks 1
• Non-pharmacological approaches (rest, physical therapy, heat/cold therapy) should be attempted first when feasible 1

Counseling Points for Patients

Advise pregnant women early in pregnancy to:

• Use paracetamol only when medically indicated (not for minor discomfort) 2, 3
• Consult a physician or pharmacist if uncertain whether use is indicated 3
• Use the lowest effective dose for the shortest possible time 2, 3
• Avoid prolonged daily use unless specifically directed by their healthcare provider 1, 4

Evidence Quality Note

While the FDA and Society for Maternal-Fetal Medicine state that evidence regarding neurodevelopmental risks remains "inconclusive" due to methodological limitations and inability to control for all confounders, multiple systematic reviews consistently show associations with prolonged exposure. 2 The precautionary principle supports minimizing duration and cumulative exposure while recognizing paracetamol remains the safest available option when analgesia is medically necessary. 2, 3