According to results of a recent Canadian study published in The British Journal of Pharmacology, certain antibiotics may increase the risk of major congenital malformations (MCMs).
Researchers used the Quebec pregnancy cohort, which included data from 1998 to 2008 and included a total of 139,938 live singleton infants whose mothers had been covered by the Régie de l'assurance maladie du Québec drug plans for at least 12 months before and during pregnancy. Exposure to antibiotics was assessed in the first trimester and MCMs were identified over the course of the first year of an infant’s life.
Following adjustment for potential confounders, exposure to clindamycin was linked with an increased risk of MCMs (adjusted odds ratio [aOR] 1.34, 95% confidence interval [CI], 1.02-1.77, 60 exposed cases), musculoskeletal system malformations (aOR 1.67, 95%CI, 1.12-2.48, 29 exposed cases), and atrial/ventricular septal defects (aOR 1.81, 95%CI, 1.04-3.16, 13 exposed cases).
Exposure to doxycycline increased the risk of circulatory system malformations, cardiac malformations, and atrial/ventricular septal defects (aOR 2.38, 95%CI ,1.21-4.67, 9 exposed cases; aOR 2.46, 95%CI, 1.21-4.99, 8 exposed cases; aOR 3.19, 95%CI, 1.57-6.48, 8 exposed cases, respectively). Associations were also seen with quinolone (1 defect), ofloxacin (1 defect), erythromycin (1 defect), phenoxymethylpenicillin (1 defect), macrolide (1 defect), and moxifloxacin (1 defect). No association was seen with nitrofurantoin, amoxicillin, or cephalosporins. When penicillins were used as a comparator group, similar results were seen.
The authors concluded that in utero exposure to certain antibiotics, such as clindamycin, doxycycline, quinolones, macrolides and phenoxymethylpenicillin, was linked to organ-specific malformations.