Concerns regarding the teratogenicity of fluoroquinolones have resulted in their restricted use during gestation. This is despite an increasing need for their use due to emerging bacterial resistance. The objectives of the present investigation were to evaluate pregnancy and fetal outcomes following maternal exposure to fluoroquinolones and to examine whether in utero exposure to quinolones is associated with clinically significant musculoskeletal dysfunctions. We prospectively enrolled and followed up 200 women exposed to fluoroquinolones (norfloxacin, ciprofloxacin, ofloxacin) during gestation. Pregnancy outcome was compared with that for 200 controls matched for age and for smoking and alcohol consumption habits. Controls were exposed to nonteratogenic, nonembryotoxic antimicrobial agents matched by indication, duration of therapy (+/- 3 days), and trimester of exposure. Rates of major congenital malformations did not differ between the group exposed to quinolones in the first trimester (2.2%) and the control group (2.6%) (relative risk, 0.85; 95% confidence interval, 0.21 to 3.49). Women treated with quinolones had a tendency for an increased rate of therapeutic abortions compared with the rate among women exposed to nonteratogens (relative risk, 4.50; 95% confidence interval, 0.98 to 20.57), resulting in lower live-birth rates (86 versus 94%; P = 0.02). The rates of spontaneous abortions, fetal distress, and prematurity and the birth weight did not differ between the groups. Gross motor developmental milestone achievements did not differ between the children of the mothers in the two groups. We concluded that the use of fluoroquinolones during embryogenesis is not associated with an increased risk of major malformations. There were no clinically significant musculoskeletal dysfunctions in children exposed to fluoroquinolones in utero. The higher rate of therapeutic abortions observed in quinolone-exposed women compared to that for their controls may be secondary to the misperception of a major risk related to quinolone use during pregnancy.