Certain medications seem safer than others, but overall danger is low, researchers say
Use of macrolides, quinolones, tetracyclines, sulfonamides, and metronidazole during pregnancy may increase the risk of miscarriage, according to a study published in the May 1 issue of CMAJ, the journal of the Canadian Medical Association.
Anick Bérard, Ph.D., a professor at the University of Montreal’s Faculty of Pharmacy, and colleagues matched 8,702 cases of spontaneous abortion with 87,020 controls by gestational age and year of pregnancy. The researchers used data from women ages 15 to 45 who were covered by Quebec’s drug insurance plan.
The team found that 16.4 percent of the women who had miscarriages were exposed to antibiotics during early pregnancy, compared to 12.6 percent of the controls. Azithromycin and clarithromycin were linked to a 65 percent and two-fold increased risk of miscarriage, respectively. Norfloxacin was associated with more than a four-fold increased risk.
“After adjustment for potential confounders, use of macrolides (excluding erythromycin), quinolones, tetracyclines, sulfonamides, and metronidazole during early pregnancy was associated with an increased risk of spontaneous abortion,” the authors write. “Our findings may be of use to policymakers to update guidelines for the treatment of infections during pregnancy.”