Is diclofenac safe in pregnancy? A comprehensive guide for expectant mothers

October 8, 2025 •

4 min read

According to the U.S. Food and Drug Administration (FDA), pregnant women should avoid taking nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac at 20 weeks gestation and later due to potential risks to the unborn baby. This critical guideline highlights the importance of understanding why is diclofenac safe in pregnancy is a complex question with serious implications for fetal health.

Quick Summary

Diclofenac use during pregnancy is associated with significant risks, particularly in the later stages, including kidney problems and heart issues for the fetus. Medical consensus recommends avoiding it from 20 weeks onward, with some studies suggesting caution throughout. Safer alternatives like acetaminophen are widely recommended for pain relief during pregnancy, while diclofenac should only be considered under strict medical supervision for specific conditions and for the shortest duration possible.

Key Points

Avoid after 20 weeks: The FDA strongly recommends avoiding diclofenac and all NSAIDs at 20 weeks of pregnancy and later due to risks of fetal kidney problems.
Risk of Oligohydramnios: Use of diclofenac after 20 weeks can cause low amniotic fluid, which is critical for fetal development and can be reversible if the medication is stopped.
Third Trimester Dangers: Diclofenac is strictly contraindicated from 30 weeks onward due to the risk of premature closure of a fetal heart vessel (ductus arteriosus) leading to Persistent Pulmonary Hypertension of the Newborn (PPHN).
Paracetamol is Safest Alternative: Acetaminophen (Paracetamol) is the preferred and safest over-the-counter painkiller recommended throughout pregnancy.
Talk to a Doctor: All medication use during pregnancy, even topical creams, should be discussed with a healthcare provider to weigh the risks and benefits.
Potential for Miscarriage: Some studies suggest a potential link between NSAID use and an increased risk of miscarriage in early pregnancy, though further research is needed.
May Affect Fertility: High or prolonged doses of NSAIDs like diclofenac can affect ovulation, potentially making it harder to conceive.

Understanding Diclofenac and Its Classification

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain, inflammation, and fever. While effective for many conditions, its use during pregnancy is highly regulated due to the potential for serious adverse effects on the fetus. NSAIDs work by blocking the production of prostaglandins, chemicals that contribute to pain and inflammation, but which also play vital roles in fetal development, particularly concerning the kidneys and circulatory system.

Trimester-Specific Risks of Diclofenac

Medical guidance on diclofenac use is broken down by trimester, reflecting the different developmental stages of the fetus and the associated risks.

First Trimester: Early Pregnancy Concerns

Some studies suggest a potential link between NSAID use in early pregnancy and an increased risk of miscarriage, though findings are sometimes conflicting. Some of these associations might be explained by the underlying medical conditions for which diclofenac was prescribed. Other research, including a study using the German Embryotox database, did not find a significant increase in the risk of major birth defects or spontaneous abortion associated with first-trimester diclofenac exposure. However, experts still advise caution due to the limited and sometimes conflicting data.

Second Trimester: The 20-Week Warning

The FDA recommends avoiding NSAID use, including diclofenac, from 20 weeks gestation and later. Between 20 and 30 weeks, diclofenac may cause fetal renal dysfunction, which can lead to low amniotic fluid (oligohydramnios). Amniotic fluid is crucial for cushioning the baby and supporting the development of its lungs and digestive system. While often reversible upon stopping the medication, prolonged oligohydramnios can lead to severe complications.

Third Trimester: Contraindicated

Diclofenac is strictly contraindicated from 30 weeks gestation onward, as it poses a critical risk to the baby's heart. In the final trimester, NSAIDs can cause premature closure of the fetal ductus arteriosus, a blood vessel necessary for proper blood circulation in the womb. This can lead to persistent pulmonary hypertension of the newborn (PPHN), a serious lung condition that can be fatal.

Medical Guidance and Safer Alternatives

Given the significant risks, health professionals advise against using diclofenac during most of pregnancy unless absolutely necessary and only under direct medical supervision.

Recommended Approach to Pain Relief

First-line treatment: Paracetamol (acetaminophen) is generally considered the safest and first-choice painkiller for use throughout all trimesters of pregnancy. It has an extensive safety profile based on its use in a large number of pregnant women.
Non-pharmacological options: For mild pain like headaches or backaches, consider non-medication approaches. These can include:
- Massage therapy
- Physical therapy
- Staying active with swimming or yoga
- Using hot or cold compresses
- Wearing supportive shoes
Consultation is key: Always discuss any pain medication needs with a doctor. A healthcare provider can assess the benefits and risks for your specific situation and, if necessary, prescribe an alternative.

Comparison of Diclofenac and Paracetamol in Pregnancy


Feature	Diclofenac (NSAID)	Paracetamol (Acetaminophen)
Recommended for First Trimester?	Use with caution, discuss with a doctor.	Yes, generally considered safe.
Recommended for Second Trimester (20-30 weeks)?	Avoid. Use only if prescribed and under strict supervision for the shortest duration possible. Risk of fetal kidney problems and oligohydramnios.	Yes, generally considered safe.
Recommended for Third Trimester (30+ weeks)?	Contraindicated. High risk of premature closure of the fetal ductus arteriosus and PPHN.	Yes, generally considered safe.
Impact on Fetal Kidneys	Can cause fetal renal dysfunction and lead to low amniotic fluid.	No known significant impact on fetal kidneys at therapeutic doses.
Impact on Fetal Heart	Significant risk of premature closure of the ductus arteriosus and PPHN in the third trimester.	No known significant impact on fetal heart.
Route of Administration	Oral, topical gel, suppositories, injectables.	Oral, rectal.
Associated Miscarriage Risk	Some conflicting studies suggest a possible link in early pregnancy.	No significant increase in miscarriage risk reported.

Important Considerations for Diclofenac During Pregnancy

Combined medications: Diclofenac is sometimes prescribed with other drugs, such as misoprostol, which is known to cause miscarriage, premature birth, and birth defects. The combination product is strictly contraindicated during pregnancy and is not recommended for women who may become pregnant.
Topical diclofenac: While oral diclofenac carries high systemic risks, topical applications (creams, gels) are generally associated with minimal systemic absorption. However, the product label for topical diclofenac (e.g., Voltaren) and other NSAIDs has been updated to include warnings regarding use in late pregnancy. It is crucial to consult a healthcare provider before using topical formulations to ensure minimal risk.
Breastfeeding: For breastfeeding mothers, diclofenac is generally considered acceptable due to the small amounts that pass into breast milk. However, healthcare providers often suggest using alternatives with more published safety data, particularly for newborns or premature infants. Ibuprofen and paracetamol are often preferred choices.
Pre-conception: NSAIDs, including diclofenac, may temporarily affect female fertility by impacting ovulation. Women who are trying to conceive or undergoing fertility treatment may be advised to avoid using diclofenac.

Conclusion: Prioritize Safety

In conclusion, is diclofenac safe in pregnancy? The consensus from major health organizations like the FDA and NHS is clear: it is not generally safe and should be avoided, especially from 20 weeks gestation onwards, due to the risk of serious fetal harm. The risks involve fetal kidney damage leading to low amniotic fluid and premature closure of the heart's ductus arteriosus, potentially causing a life-threatening condition in newborns. Paracetamol is the recommended first-line pain reliever for expectant mothers, and non-drug therapies should also be explored. Always consult a healthcare provider for the safest options for you and your baby.

Frequently Asked Questions

While topical forms of diclofenac are associated with lower systemic absorption than oral versions, the FDA guidelines recommending avoidance of NSAIDs after 20 weeks of pregnancy still apply. It is best to avoid topical diclofenac after 20 weeks unless advised by a doctor, who will weigh the risks and benefits.

The primary risk of taking diclofenac after 30 weeks of pregnancy is the premature closure of the fetal ductus arteriosus, a vital blood vessel. This can lead to Persistent Pulmonary Hypertension of the Newborn (PPHN), a serious and potentially fatal heart and lung condition.

If you took diclofenac before you knew you were pregnant, especially in the early stages, contact your doctor as soon as possible. Short-term use early in pregnancy is generally not expected to cause harm, but your healthcare provider may want to discuss the situation with you.

Paracetamol (acetaminophen) is widely recommended as the safest choice for pain relief during all trimesters of pregnancy. Non-drug options like massage, hot/cold packs, and prenatal yoga can also provide relief.

Yes, taking high doses or prolonged courses of NSAIDs, including diclofenac, may affect ovulation in some women, potentially making it more difficult to conceive. Experts advise stopping NSAID use if you are trying to become pregnant.

Yes, diclofenac is generally considered acceptable for use while breastfeeding, as only minimal amounts pass into breast milk. However, other medications like ibuprofen or paracetamol are often preferred as they have more extensive safety data regarding use during lactation.

The FDA updated its recommendation in 2020 after reviewing cases linking NSAID use as early as 20 weeks gestation to fetal kidney problems and low amniotic fluid (oligohydramnios). The change was made to better protect unborn babies from these earlier-occurring risks.