Non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat pain and inflammation in various disease states.  Currently available NSAIDs in the UK (including both COX2 selective and non-selective agents) are aceclofenac, acemetacin, azapropazone, celecoxib, dexibuprofen, dexketoprofen, diclofenac, etodolac, etoricoxib, fenbufen, fenoprofen, flurbiprofen, ibuprofen, indometacin, ketoprofen, ketorolac, trometamol, mefenamic acid, meloxicam, nabumetone, naproxen, parecoxib, piroxicam, sulindac, tenoxicam and tiaprofenic acid. 

The available data on NSAIDs generally do not indicate that exposure before 30 weeks of pregnancy is associated with an increased risk of malformations.  While recent data have suggested that there may be an increased risk of cardiac malformations associated with NSAID use in early pregnancy, this finding has not been confirmed.  An increased risk of spontaneous abortion following maternal exposure to NSAIDs during pregnancy has been suggested, but has not been conclusively proven. 

Exposure to NSAIDs after 30 weeks of pregnancy is associated with an increased risk of premature closure of the ductus arteriosus and oligohydramnios. These effects are related to the inhibitory effect of NSAIDs on prostaglandin activity.  The incidence and severity of premature closure of the ductus arteriosus appears to be dose related and increases with advancing gestational age beyond 30 weeks.

If an NSAID is clinically indicated in the first or second trimester, ibuprofen would be the preferred agent. NSAIDs should, where possible, be avoided during the third trimester. In circumstances where the clinical condition requires treatment with NSAIDs during the third trimester, the fetus should be monitored regularly for oligohydramnios and to ensure normal circulation.  Fetal circulation should be monitored via fetal echocardiogram following any NSAID exposure in late pregnancy.  Oligohydramnios may be detected through serial scans measuring amniotic fluid volume and growth.  Detection of an abnormality following third trimester exposure to an NSAID warrants referral to a fetal medicine unit for further investigation.  Provided that there are no other risk factors involved, inadvertent exposure to NSAIDs at any stage of pregnancy does not constitute medical grounds for termination of pregnancy.

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