The US Food and Drug Administration (FDA) has warned against using nonsteroidal anti-inflammatory drugs (NSAIDs) from 20 weeks into pregnancy. They say that usage of the drugs may cause a rare but serious kidney problem to the unborn child. While a well-known risk among certain medical specialties, the announcement comes as an effort to communicate more widely to other specialties and pregnant women.
After around 20 weeks of gestation, unborn babies' kidneys produce most of the amniotic fluid they need- the protective cushion that helps their lungs, digestive system, and muscles develop. Kidney problems caused by the usage of NSAIDs can lead to lower levels of this fluid being produced, which can then lead to further health complications.
The recommendations are the result of a review of medical literature, including case reports, randomized control studies, and observational studies. While most of the publications suggest that the condition, known as oligohydramnios, tends to occur in the third trimester, some reported an earlier onset from around 20 weeks of gestation.
The review also stated that, in most cases, oligohydramnios was reversible within 72 hours to 6 days of discontinuing usage of the NSAID.
"It is important that women understand the benefits and risks of the medications they may take over the course of their pregnancy," says Patrizia Cavazzoni, MD, acting director of FDA's Center for Drug Evaluation and Research. "To this end, the agency is using its regulatory authority to inform women and their healthcare providers about the risks if NSAIDs are used after around 20 weeks of pregnancy and beyond."
The announcement comes after previous warnings against using NSAIDs, including ibuprofen and celecoxib, after week 30 of pregnancy due to heart-related risks. As such, manufacturers of NSAIDs will now be required to update their labeling.
The FDA mentioned, however, that a low-dose (81mg) aspirin is excluded from the precaution. They also mentioned that if a healthcare provider believes that NSAIDs are necessary for women between week 20 and 30 of pregnancy, their usage should be limited to the lowest effective dose for the shortest duration possible.