According to a new publication recently published in the British Medical Journal (BMJ), by Dr. DeKun Li, use of NSAIDs and aspirin during pregnancy increased the risk of miscarriage. However, Dr. Li does caution that these findings need further confirmation in studies designed specifically to examine the apparent association. Dr. Li is a research scientist at Kaiser Permanente’s Division of Research located in Oakland, California.
The study objective was to evaluate whether prenatal use of non-steroidal anti-inflammatory drugs (NSAIDs) was associated with increased risk of miscarriage. The population based cohort study, ascertained prenatal use of NSAIDs, aspirin, and acetaminophen (paracetamol) by in-person interview. The study subjects were sampled from the Kaiser Permanente Medical Care Program, a healthcare delivery system, in the San Francisco area of the United States. Participants included 1055 pregnant women who were recruited and interviewed immediately after their positive pregnancy test. The median gestational age at entry to the study was 40 days.
Pregnancy outcomes up to 20 weeks of gestation were the main outcome measure. The study results indicated that 53 women (5%) reported prenatal NSAID use around conception or during pregnancy. After adjustment for potential confounders, prenatal NSAID use was associated with an 80% increased risk of miscarriage (adjusted hazard ratio 1.8 (95% confidence interval 1.0 to 3.2)). The association was stronger if the initial NSAID use was around the time of conception or if NSAID use lasted more than a week. Prenatal aspirin use was similarly associated with an increased risk of miscarriage. However, prenatal use of acetaminophen (paracetamol), pharmacologically different from NSAIDs and aspirin, was not associated with increased risk of miscarriage regardless of timing and duration of use.
In sum, and as noted above, prenatal use of NSAIDs and aspirin increased the risk of miscarriage. However, these findings need further confirmation in studies designed specifically to examine the apparent association.