Is it safe for a pregnant patient to use diclofenac (Nonsteroidal Anti-Inflammatory Drug (NSAID)) gel for local pain relief?

Diclofenac Gel During Pregnancy: Safety Recommendations

Diclofenac gel should be avoided during pregnancy, particularly after 20 weeks gestation, due to significant fetal risks including oligohydramnios and premature ductus arteriosus closure, even with topical application. 1, 2, 3

Gestational Age-Specific Guidance

First Trimester (Weeks 0-13)

• Topical diclofenac can be used cautiously if clinically necessary during the first trimester, as current evidence shows no increased risk of miscarriage or congenital malformations with early pregnancy NSAID exposure 1, 2, 4
• 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 4
• Use the lowest effective dose for the shortest possible duration (ideally 7-10 days maximum) 1, 2
• Consider acetaminophen as the preferred first-line analgesic instead, as it has the most extensive safety data across all trimesters 2

Second Trimester (Weeks 14-28)

• Discontinue diclofenac gel after week 20 if possible due to emerging fetal renal risks 1, 2, 3
• If use extends beyond 48 hours after week 20, ultrasound monitoring for oligohydramnios is recommended 3
• Two case reports documented reversible oligohydramnios at gestational weeks 22 and 23 following long-term diclofenac exposure (≥150 mg/day oral), which resolved after discontinuation 5
• The FDA label explicitly warns that NSAID use at about 20 weeks gestation or later has been associated with fetal renal dysfunction leading to oligohydramnios 3

Third Trimester (Week 28 and Beyond)

• Absolute contraindication for diclofenac gel after week 28-30 1, 2, 3
• Critical fetal risks include:
  • Premature closure of the ductus arteriosus 1, 3, 6
  • Oligohydramnios from fetal renal dysfunction 1, 3, 5
  • Neonatal renal failure (potentially irreversible) 7
  • Pulmonary hypertension in the newborn 1
• A case report documented severe fetal complications (ascites, tricuspid regurgitation, constricted ductus arteriosus) after just six doses of oral diclofenac 50 mg at 36 weeks gestation 6

Critical Clinical Considerations

Systemic Absorption from Topical Application

• While topical diclofenac has lower systemic absorption than oral formulations, it still carries the same pregnancy risks 8, 3
• The FDA label for topical diclofenac explicitly includes the same pregnancy warnings as oral NSAIDs, indicating that topical application does not eliminate fetal risk 3
• Guidelines recommend considering topical NSAIDs (including diclofenac gel) for cancer-related bone pain with "minimal systemic effects," but this does not negate pregnancy contraindications 8

Fertility Implications

• Women actively trying to conceive should discontinue diclofenac gel, as NSAIDs can interfere with ovulation through luteinized unruptured follicle (LUF) syndrome 1, 2, 3
• If used while attempting conception, use intermittently rather than continuously 1

Safer Alternatives

Pharmacological Options

• Acetaminophen is the preferred analgesic across all trimesters (use lowest effective dose for shortest duration) 2, 9
• Ibuprofen has slightly more reassuring safety data than diclofenac for first and second trimester use if an NSAID is absolutely required 1, 2
• For chronic inflammatory conditions requiring long-term treatment, pregnancy-compatible alternatives include hydroxychloroquine, sulfasalazine (with folate supplementation), low-dose prednisone (≤5-10 mg daily), azathioprine, and colchicine 1

Non-Pharmacological Options

• Transcutaneous electrical nerve stimulation (TENS therapy) 9
• Kinesio tapes 9
• Acupuncture 9
• Lymphatic drainage for edema (if not caused by preeclampsia) 9

Common Pitfalls to Avoid

• Do not assume topical application is safe simply because systemic absorption is lower—the FDA label and guidelines apply the same restrictions to topical diclofenac as oral formulations 3
• Do not continue use beyond week 20 without compelling indication and close fetal monitoring 1, 2, 3
• Do not prescribe after week 28-30 under any circumstances due to risk of irreversible fetal harm 1, 2, 3, 7
• Avoid combining with other NSAIDs or aspirin, which increases gastrointestinal and cardiovascular risks without improving efficacy 3

Breastfeeding Safety

• Diclofenac is considered safe during breastfeeding with minimal excretion in breast milk 10
• Ibuprofen has the most reassuring safety data among NSAIDs during lactation, followed by diclofenac as the second safest option 10
• No need to interrupt breastfeeding or discard breast milk when using diclofenac 10