The risk of miscarriage is more than doubled in women who take any dose of non-aspirin NSAIDs in early pregnancy compared with women who do not take the drugs, a study has found.
Of 4,705 cases of miscarriages recorded in the Quebec Pregnancy Registry before the 20th week of gestation, 7.5% had used non-aspirin NSAIDs, identified by records of filled prescriptions. Of the 47,050 women in the control group who did not miscarry, 2.6% had taken nonaspirin NSAIDs.
After adjusting the results for confounding variables, the use of non-aspirin NSAIDs during pregnancy was significantly associated with a 2.4-fold dose-independent increased risk of miscarriage.
The highest risk was in patients who used diclofenac alone – who had more than a three-fold risk, while the lowest risk was in those who took rofecoxib alone – who had an 80% higher risk.
Study leader Dr Hamid Reza Nakhai-Pour, clinical epidemiologist at the University of Montreal, concluded: ‘Our results suggest a class effect on the risk of clinically detected spontaneous abortion. Non-aspirin NSAIDs should be used with caution during pregnancy', he added.
CMAJ 2011, online 6 September