Ibuprofen Doesn't Boost Miscarriage Risk, Israeli Study Shows

Previous studies on pregnant women and nonsteroidal anti-inflammatory drugs have had inconsistent results.

Women who take nonsteroidal anti-inflammatory drugs during pregnancy do not face an increased risk of miscarriage, a new study conducted by Israeli researchers and published on Monday shows.

Pregnant women have used the class of drugs commonly referred to as NSAIDS – including ibuprofen, naproxen, diclofenac – during the first trimester, but have been dissuaded from taking them, particularly during the third trimester. The drugs have been linked to pulmonary problems in newborns, as well as premature birth and, in some cases, spontaneous abortion or miscarriage.

According to the new study's authors, it was unclear until now whether the drugs increased the risk of miscarriage, because previous studies have had inconsistent results. However, they said their research confirmed that NSAIDs do not increase the chances a woman will miscarry.

"We found no important associations between exposure to NSAIDs, either by group or for most specific NSAID drugs, and risk of spontaneous abortion," wrote Dr. Sharon Daniel and Prof. Amalia Levy, from the department of public health at Ben-Gurion University of the Negev and Soroka University Medical Center, both in the southern Israeli city of Be'er Sheva.

The research was published in the Canadian Medical Association Journal.

The study examined data on 65,457 women, aged 15 to 45, who were admitted to Soroka University Medical Center between January 2003 and December 2009. Ninety percent of those were admitted to give birth while the remaining 10 percent suffered miscarriages.

Of the total group, 4,495 (6.9 percent) of women had taken NSAIDs during their first trimester of pregnancy. About 8.2 percent of women in the group exposed to NSAIDs had miscarriages compared with 10 percent of women in the group that did not take the class of drugs.

The study found that women who took NSAIDs were older, more likely to smoke and had more inflammatory diseases – and more of them had undergone in-vitro fertilization (IVF) than in the group that didn’t take the drugs.

"The fact that the study was based on a large proportion of the district population, was adjusted to nearly all known risk factors for miscarriages…and used advanced statistical methods strengthens the validity of the results," said Prof. Levy.

The study did, however, find an increased risk of miscarriage with one specific drug – indomethacin – possibly because it was dispensed at the end of pregnancy, likely to treat preterm labor.

It also found that, among women who took COX-2 selective inhibitors, which target a specific enzyme responsible for inflammation and pain, 17% miscarried.

That group was smaller, though, and requires further research, the study's authors said.

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