[Risks of antibacterial agents in pregnancy]

Antimicrobial therapy in the pregnant woman has to consider the potential risks of antibacterial agents for the developing foetus and the mother. Extensive clinical experience shows that penicillins, cephalosporins and erythromycin (except erythromycin estolate) can be considered safe for the developing foetus and for the pregnant woman. Nitrofurantoin is a valid antibacterial option in pregnancy, except in the latter stages. Isoniazid and ethambutol are the safest drugs for the treatment of tuberculosis in pregnancy, but attention must be paid to the potential toxicity of isoniazid for the mother. For several other antimicrobial agents (aminoglycosides, fluoroquinolones, newer macrolides, metronidazole, rifampicin, vancomycin) a potential teratogenic or toxic risk has been documented in animal or human studies: however, their use during pregnancy is justified when there is no safer alternative. A few antibacterials should be absolutely avoided in pregnancy: tetracyclines, cotrimoxazole and chloramphenicol according to a teratogenic risk or a toxic risk for the foetus or the mother, and clindamycin according to its high risk/benefits ratio. The safety data in pregnancy of many other antibacterials, including carbapenems, ketolides and streptogramines, are very limited or lacking. More data on the risks of antibacterial agents are needed for an optimal therapy of bacterial infections in pregnancy.