June 17, 2015 -- Young women who regularly use pain-relief medicines called NSAIDs (nonsteroidal anti-inflammatory drugs) might be seriously undermining their fertility, a new study suggests.
The popular drugs, some of them available without a prescription, may hinder ovulation and lower levels of the female hormone progesterone, the researchers say.
Although "this process is reversible, a woman is not going to get pregnant if she continues to take NSAIDs, and doctors need to advise women to stop taking these drugs if they want to be fertile," says Sami Salman, MD, from the University of Baghdad.
Salman presented the study results at the European League Against Rheumatism Congress 2015 in Rome.
'A Shocking Finding'
The researchers evaluated 39 women of childbearing age who had minor back pain.
The women received one of four treatments. They included the NSAIDs diclofenac, etoricoxib, naproxen, and a placebo. (Diclofenac is available only by prescription. Etoricoxib hasn’t been FDA-approved for use in the U.S.)
Before starting their treatments, each woman got an ultrasound. The researchers wanted to check on the size of their ovaries, which grow important things called follicles each month. The follicles "rupture" and release an egg when a woman ovulates, but the researchers believe NSAIDs may keep that process from happening.
They also measured the women's progesterone levels. The hormone is essential for ovulation and for helping a fertilized egg attach to the lining of a mom-to-be's womb.
The women began getting their treatments on day 10 of their menstrual cycle. That ensured a follicle had developed in preparation for releasing an egg, Salman says.
After 10 straight days on the treatment regimen, the women got another ultrasound so researchers could check on the effects.
"Ovulation was far less frequent in patients who were on NSAIDs," Salman says.
"For those taking diclofenac, ovulation was reduced by an amazing 93%, whereas for both naproxen and etoricoxib, ovulation was reduced by about 75%," he says. "This was really a shocking finding."
The women's progesterone levels had dropped, too.
About one-third of the women developed a cyst because of unruptured follicles, Salman says.
Next, the researchers convinced about half of the women to return the next month for a check of their ovulation. After they stopped taking NSAIDs, all the women "did ovulate normally during the next cycle," Salman says.
Although the reported consequences of using the drugs seemed reversible, “these findings highlight the harmful effects NSAIDs may have on fertility,” and may open the door to new emergency contraception methods, Salman says.
The study "reminds us that we should be knowledgeable about uncommon side effects of drugs we use frequently," says Philip Conaghan, MD, from the University of Leeds in the U.K. "The potential negative effects of NSAIDs on fertility have been reported for many years."
Conaghan says that most people who take NSAIDs use them occasionally, are postmenopausal women, or both. But he says rheumatologists see a lot of younger women -- for whom fertility is often an issue -- with inflammatory diseases who use these drugs frequently.
"This work is a timely reminder to consider the role and timing of NSAIDs" in these women, he says.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.