NSAIDs in Early Pregnancy Linked to Risk for Miscarriage

September 6, 2011

Use of nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs) in early pregnancy is linked to twice the risk for miscarriage, according to the results of a nested case-control study reported online September 6 in the Canadian Medical Association Journal.

“The association between the use of …NSAIDs during pregnancy and the risk of spontaneous abortion remains unclear because of inconsistent research results and the lack of evidence for an effect due to specific types or dosages of nonaspirin NSAIDs,” write Hamid Reza Nakhai-Pour, MD, PhD, from the University of Montreal and CHU Ste-Justine in Quebec, Canada, and colleagues. “We aimed to quantify the association between having a spontaneous abortion and types and dosages of nonaspirin NSAIDs in a cohort of pregnant women.”

Case patients consisted of 4705 women who were identified from the Quebec Pregnancy Registry and who had a spontaneous abortion. For each case patient, the investigators randomly selected 10 control participants from other women in the registry, matching by index date, defined as the date of the spontaneous abortion, and by gestational age. Case patients and control participants were compared in use of nonaspirin NSAIDs, as reflected in filled prescriptions. The investigators analyzed associations between different types and dosages of nonaspirin NSAIDs and spontaneous abortion using conditional logistic regression, with adjustment for confounding variables.

Of the 4705 patients with spontaneous abortion, 352 (7.5%) had NSAID exposure, as did 1213 (2.6%) of 47,050 control participants. The use of nonaspirin NSAIDs during pregnancy was significantly associated with the risk for spontaneous abortion, after adjustment for potential confounders. There was no apparent dose-response effect.

“Gestational exposure to any type or dosage of nonaspirin NSAIDs may increase the risk of spontaneous abortion,” the study authors write.

“Given that the use of nonaspirin NSAIDs during early pregnancy has been shown to increase the risk of major congenital malformations and that our results suggest a class effect on the risk of clinically detected spontaneous abortion, nonaspirin NSAIDs should be used with caution during pregnancy,” the study authors conclude. “Future research should focus on determining exact mechanisms of action.”

This is a summary of the MedScape Today news report.

For those wishing to read the actual study, here is the citation:

Hamid Reza Nakhai-Pour MD PhD, Perrine Broy BSc, Odile Sheehy MSc, Anick Bérard PhD

“Use of nonaspirin nonsteroidal anti-inflammatory drugs during pregnancy and the risk of spontaneous abortion” CMAJ 2011. DOI:10.1503/cmaj.110454