NSAIDs Linked with Miscarriages

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to reduce pain and inflammation. Less commonly known is the fact that they increase the risk of miscarriages.

The most popular forms of NSAIDs include aspirin. acetominophen, naproxen, ibuprofen and diclofenac.

These are typically available over the counter, but that doesn’t mean they don’t come without side effects.

Some of the side effects of NSAIDs include gastrointestinal effects, such as ulcers and heartburn. Aspirin also thins the blood.

Now we find another side effect of NSAIDs – particularly non-aspirin types: They may increase the risk of miscarriage.

Miscarriage and NSAIDs

A new study from University of Montreal researchers has found that women who used non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) during their pregnancy had almost two and a half times more incidence of miscarriage than women who did not use NSAIDs during pregnancy.

The study, published in the Journal of the Canadian Medical Association, studied the medical records of 67,160 women between 15 and 45 years old from the Quebec Pregnancy Registry. A total of 4,705 had miscarriages, and they were matched with 47,050 controls – those with healthy births.

The study excluded women who had a planned abortion, miscarried before 20 weeks gestation or were known to have been exposed to teratogens – exposures other than NSAIDs known to cause miscarriage or fetal disfigurement.

The definition of NSAID exposure for this study was at least one prescription of a nonaspirin NSAID. The women who had miscarriage were three times as likely to have had a nonaspirin NSAID prescription during their pregnancy –  7.5% for the miscarriage group versus 2.6% for the control group.

After adjustments for possible confounders, the adjusted increased miscarriage incident rate was nearly two-and-a-half times. The study did not measure the effects of aspirin.

Of the different NSAIDs, those who were prescribed diclofenac had the greatest risk of miscarriage, with more than three times the incidence. However, naproxen was the most common NSAID used, and naproxen use was associated with more than two and a half times the miscarriage incidence.

Celecoxib and ibuprofen had well over twice the incidence, while rofecoxib had just under twice (1.83) the incidence of miscarriage.

The researchers concluded:

“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.”

Many women take NSAIDs during pregnancy

It has been estimated that about 17 percent of pregnant women use some type of non-aspirin NSAID during their pregnancy. Other studies have found that NSAID use close to conception have caused problems for the baby and birth. This of course relates to birthing pain. In this study, miscarriage increased to three and a half times for women given NSAIDs during the two week period prior to birth or miscarriage.

Still other studies have shown that some NSAIDs, such as acetominophen, also can cause liver damage.

Research has also shown that a number of herbs, including willow bark and meadowsweet, can decrease pain and inflammation comparable to NSAIDs. Some herbs help prevent miscarriage. And this herb beats NSAIDS in reducing pain according to other research.

REFERENCES

Nakhai-Pour HR, Broy P, Sheehy O, Bérard A. Use of nonaspirin nonsteroidal anti-inflammatory drugs during pregnancy and the risk of spontaneous abortion. CMAJ. 2011 Sept 6. doi: 10.1503/cmaj.110454