tokens: 9 ). Other antibacterial agents that showed associations included erythromycins ( 2 defects ), penicillins ( 1 defect ), cephalosporins ( 1 defect ), and quinolones ( 1 defect ). CONCLUSIONS : Reassuringly , penicillins , erythromycins , and cephalosporins , although used commonly by pregnant women , were not associated with many birth defects .