There have been no studies on the safety of moxifloxacin during pregnancy. Reproductive studies in rats and monkeys did not show any evidence of teratogenicity or fertility disturbances. However, like other quinolones, moxifloxacin has been shown to cause cartilage lesions in the weight-bearing joints of immature animals. Preclinical data suggest that moxifloxacin is excreted into breast milk. The use of moxifloxacin is contraindicated in pregnant and breastfeeding mothers.