Diclofenac in the Third Trimester of Pregnancy
Diclofenac is absolutely contraindicated in the third trimester of pregnancy due to significant risks of premature closure of the fetal ductus arteriosus, oligohydramnios, and neonatal renal impairment. 1, 2
Risks of Diclofenac in Third Trimester
The FDA drug label explicitly states that NSAIDs including diclofenac should be avoided at about 30 weeks gestation and later in pregnancy due to the following serious risks 2:
- Premature closure of the fetal ductus arteriosus - This can lead to pulmonary hypertension in the newborn
- Oligohydramnios - Reduced amniotic fluid volume due to fetal renal dysfunction
- Neonatal renal impairment - Can persist after birth
Multiple medical guidelines strongly contraindicate all NSAIDs after gestational week 28 1. Even before 28 weeks, caution is warranted as case reports have documented:
- Reversible oligohydramnios occurring as early as gestational weeks 22-23 with high-dose, long-term diclofenac use (≥150mg/day) 3
- Complete closure of the ductus arteriosus at 35 weeks following maternal diclofenac therapy 4
Alternative Pain Management Options
For pregnant women requiring pain management in the third trimester:
Acetaminophen (Paracetamol) - First-line treatment considered safe throughout pregnancy 1
For inflammatory conditions requiring treatment after 32 weeks:
- Low-dose prednisone (≤5 mg/day) may be used throughout pregnancy 1
Important Clinical Considerations
A study found approximately 3% of women still use NSAIDs close to labor despite contraindications, indicating many women remain unaware of these risks 5
If NSAID exposure has already occurred in the third trimester:
- Monitor with ultrasound for oligohydramnios
- Discontinue diclofenac immediately if oligohydramnios is detected
- Follow up according to clinical practice 2
While short-term NSAID use in the second trimester appears relatively safe, long-term use in late second trimester should be monitored as it may cause similar adverse effects as third-trimester use 6, 7
Summary of NSAID Safety During Pregnancy
| Trimester | Diclofenac Safety |
|---|---|
| First | Relatively safe for short-term use |
| Second | Relatively safe for short-term use; caution with prolonged use |
| Third | AVOID COMPLETELY |
The evidence is clear and consistent across multiple high-quality sources that diclofenac and other NSAIDs should be strictly avoided during the third trimester of pregnancy due to well-documented serious risks to fetal health and development.