Can a pregnant woman safely use diclofenac for pain or inflammation, and what are the associated risks and recommended alternatives?

Diclofenac Use During Pregnancy

Diclofenac can be used cautiously in early pregnancy (first trimester and early second trimester) with no evidence of increased teratogenic risk, but must be discontinued after gestational week 28 to avoid serious fetal complications including premature ductus arteriosus closure and oligohydramnios. 1

Timing-Based Recommendations

First Trimester (Weeks 0-13)

• Early pregnancy exposure to diclofenac shows no evidence of increased risk of miscarriage or teratogenicity 1
• Reassuring data available for diclofenac, though ibuprofen has the most extensive safety data among NSAIDs 1
• A prospective cohort study of 260 women exposed to diclofenac in the first trimester found no increased rate of major birth defects (1.8% vs. 3.1% in controls) or spontaneous abortion 2

Second Trimester (Weeks 14-28)

• Short-term use (7-10 days maximum) does not appear to pose substantial fetal risks 1
• Use the lowest effective dose for the shortest possible duration 1
• Must discontinue after gestational week 28 (end of second trimester) 1
• Caution: Two case reports documented reversible oligohydramnios at weeks 22-23 with high-dose diclofenac (≥150 mg/day), which resolved after discontinuation 3

Third Trimester (Week 29 onwards)

• Absolutely avoid diclofenac at approximately 30 weeks gestation and later 4
• Risk of premature closure of fetal ductus arteriosus increases significantly 1, 4
• Risk of oligohydramnios and fetal renal dysfunction 1, 4
• Increased maternal vaginal bleeding risk (adjusted OR 1.8,95% CI 1.1-3.0) 5

Critical Fetal Risks After Week 20

Renal Complications

• If diclofenac is necessary at or after 20 weeks gestation, limit to lowest effective dose and shortest duration possible 4
• If treatment extends beyond 48 hours, consider ultrasound monitoring for oligohydramnios 4
• Discontinue immediately if oligohydramnios occurs 4

Cardiovascular Complications

• Premature closure or narrowing of the fetal ductus arteriosus 1
• Sensitivity to NSAID-related cardiovascular risks increases substantially in late pregnancy 1

Additional Considerations

Fertility Impact

• Women with difficulty conceiving should discontinue diclofenac 1
• NSAIDs can interfere with ovulation by inducing luteinized unruptured follicle (LUF) syndrome 1
• Continuous periovulatory exposure reduces fecundability 1

Safer Alternatives

• Acetaminophen (paracetamol) is the preferred first-line analgesic during pregnancy, though should be used at the lowest effective dose for the shortest duration 6, 7
• Ibuprofen has the most reassuring safety data among NSAIDs if an NSAID is required 1
• Non-pharmacological options include TENS therapy, kinesio tapes, and acupuncture 7

Common Pitfalls to Avoid

• Do not assume all NSAIDs are equally safe - diclofenac has less safety data than ibuprofen 1
• Do not continue diclofenac beyond week 28 regardless of indication 1
• Do not use high doses (≥150 mg/day) for prolonged periods even before week 28 due to oligohydramnios risk 3
• Do not prescribe COX-2 inhibitors during pregnancy - limited safety data and not recommended 7