Is topical diclofenac (Nonsteroidal Anti-Inflammatory Drug (NSAID)) safe during pregnancy?

From the Guidelines

Topical diclofenac should be avoided during pregnancy, especially in the third trimester, due to the potential risks to the developing fetus, as recommended by the 2020 American College of Rheumatology guideline 1. The use of topical diclofenac in pregnancy is a concern due to its potential effects on the fetus, particularly in the third trimester. According to the American College of Rheumatology guideline, NSAIDs, including diclofenac, are contraindicated in the third trimester because of the risk of premature closure of the ductus arteriosus 1. Some key points to consider when evaluating the use of topical diclofenac in pregnancy include:

• The potential risks to the fetus, including premature closure of the ductus arteriosus, pulmonary hypertension, and delayed labor 1
• The limited systemic absorption of topical NSAIDs, which may still pose a risk to the developing fetus 1
• The availability of safer alternatives for pain management during pregnancy, such as acetaminophen (paracetamol) or non-pharmacological approaches like physical therapy or heat/cold therapy 1 In the first and second trimesters, if pain relief is absolutely necessary, topical diclofenac may be used at the lowest effective dose for the shortest duration possible, and only after consulting with a healthcare provider. However, the potential risks and benefits should be carefully weighed, and safer alternatives should be considered whenever possible. The mechanism of action of NSAIDs, which inhibit prostaglandin synthesis, plays a crucial role in fetal development, particularly in the cardiovascular and renal systems, and this should be taken into account when making decisions about their use in pregnancy 1.

From the FDA Drug Label

Fetal Toxicity: Limit use of NSAIDs, including diclofenac sodium topical solution, between about 20 to 30 weeks in pregnancy due to the risk of oligohydramnios/fetal renal dysfunction. Avoid use of NSAIDs in women at about 30 weeks gestation and later in pregnancy due to the risks of oligohydramnios/fetal renal dysfunction and premature closure of the fetal ductus arteriosus ( 5.11,8. 1). Inform pregnant women to avoid use of diclofenac sodium topical solution and other NSAIDs starting at 30 weeks gestation because of the risk of the premature closing of the fetal ductus arteriosus [see Warnings and Precautions ( 5. 11)] . If treatment with diclofenac sodium topical solution is needed for a pregnant woman between about 20 to 30 weeks gestation, advise her that she may need to be monitored for oligohydramnios, if treatment continues for longer than 48 hours [see Warnings and Precautions ( 5.11) and Use in Specific Populations ( 8. 1)] .

The use of topical diclofenac in pregnancy is associated with fetal toxicity risks, including oligohydramnios and premature closure of the fetal ductus arteriosus.

• Avoid use of topical diclofenac in women at about 30 weeks gestation and later in pregnancy.
• If used between 20 to 30 weeks gestation, monitor for oligohydramnios if treatment continues for longer than 48 hours 2 2.

From the Research

Topical Diclofenac in Pregnancy

• The provided studies do not directly address the use of topical diclofenac in pregnancy, but rather focus on the oral or systemic use of non-steroidal anti-inflammatory drugs (NSAIDs), including diclofenac.
• However, it is known that NSAIDs, including diclofenac, can cross the placenta and may cause embryo-fetal and neonatal adverse effects, depending on the type of agent, the dose and duration of therapy, the period of gestation, and the time elapsed between maternal NSAID administration and delivery 3.
• The risk of premature closure of the ductus arteriosus is associated with NSAID use after 30 weeks' gestation 3, 4.
• A case report describes a situation where maternal diclofenac medication in pregnancy caused in utero closure of the fetal ductus arteriosus and hydrops 5.
• A prospective observational cohort study found that diclofenac exposure during the first trimester was not associated with an increased risk of major birth defects or spontaneous abortion 6.
• It is essential to note that the studies provided do not specifically address the safety of topical diclofenac in pregnancy, and more research would be needed to determine its safety profile.
• In general, NSAIDs should be given in pregnancy only if the maternal benefits outweigh the potential fetal risks, at the lowest effective dose and for the shortest duration possible 3.