Potential harms of NSAID use during pregnancy

In general, nonsteroidal anti-inflammatory drugs (NSAIDs) should be avoided in pregnancy because of the risk of:

  • miscarriage in early pregnancy; however, data are conflicting
  • oligohydramnios via effects on fetal kidney function when an NSAID is used after 20 weeks gestation
  • premature closure of the ductus arteriosus, and delayed labour and birth, when an NSAID is used after 30 weeks gestation
  • peripartum haemorrhage, especially with complicated deliveries, due to effects on maternal platelet function.
Note: In general, NSAIDs should be avoided in pregnancy and must be avoided after 30 weeks gestation.

COX-2–selective NSAIDs should be avoided from planned conception and throughout pregnancy because of a lack of data to demonstrate their safetyAustralian Rheumatology Association, 2022Flint, 2016.

A 2014 population-wide cohort study that adjusted for potential confounders found no increase in the risk of miscarriage in people taking NSAIDs in early pregnancy1Daniel, 2014. However, guidelines still recommend avoiding NSAIDs or using NSAIDs with caution in pregnant people up to 8 weeks gestation2 because of older data suggesting an increased risk of miscarriage in people taking NSAIDs in early pregnancyAustralian Rheumatology Association, 2022Flint, 2016. A lack of controlling for increased maternal age in the study designs may have confounded the results.

1 Daniel S, Koren G, Lunenfeld E, Bilenko N, Ratzon R, Levy A. Fetal exposure to nonsteroidal anti-inflammatory drugs and spontaneous abortions. CMAJ 2014;186(5):E177-82. [URL]Return
2 See the Australian Rheumatology Association Prescriber’s information on medications for rheumatic diseases in pregnancy.Return