NSAIDs increase miscarriage risk in early pregnancy

September 21, 2011

Nonsteroidal anti-inflammatory drugs (NSAIDs) should be used with caution during pregnancy, as exposure may increase the risk of spontaneous abortion, reported a study published online September 6 in the Canadian Medical Association Journal.

Nonsteroidal anti-inflammatory drugs (NSAIDs) should be used with caution during pregnancy, as exposure may increase the risk of spontaneous abortion, reported a study published online September 6 in the Canadian Medical Association Journal.

Working with data from the Quebec Pregnancy Registry, an ongoing registry of all pregnancies occurring in Quebec since 1997, researchers used a nested case-control study to assess the risk of spontaneous abortion associated with several types and dosages of nonaspirin NSAIDs in a cohort of 4,705 pregnant women. Cases were defined as those with a clinically detected spontaneous abortion occurring between the start of pregnancy and 20 weeks’ gestation. The calendar date of the clinically detected spontaneous abortion was the index date. Ten controls were randomly selected among pregnant women who did not have a spontaneous abortion but were at risk (n=47,0500). The controls were matched to each case by index date and gestational age.

After adjustment for potential confounders, the results indicated that the use of nonaspirin NSAIDs during early pregnancy is associated with a statistically significant 2.4-fold increased risk of spontaneous abortion (OR=2.43; 95% CI, 2.12–2.79; 4,705 cases, of which 352 were exposed). The highest risk was seen among women who used diclofenac alone (OR=3.09; 95% CI, 1.96–4.87); the lowest risk was seen among women who used rofecoxib alone (OR=1.83, 95% CI, 1.24–2.70).

“We consistently saw that the risk of having a spontaneous abortion was associated with gestational use of diclofenac, naproxen, celecoxib, ibuprofen, and rofecoxib alone or in combination, suggesting a class effect. We did not see a dose-response relationship,” the researchers wrote.