Fig 3.

Associated risk of major birth defects with the use of individual macrolides compared with the use of penicillin in pregnancy. The risk of any major birth defect and specific subgroups of birth defects in women who used individual macrolides in the first trimester were compared with their respective matched women who used penicillin (that is, phenoxymethylpenicillin, matched in a 1:1 ratio). In 468 pregnancies, clarithromycin was used and any major birth defects occurred in 15 pregnancies compared with 19 among pregnancies where penicillin was used (relative risk ratio 0.79; 95% confidence interval 0.41 to 1.54). For the analyses of specific subgroups of birth defects, only heart defects (seven v four, respectively; relative risk ratio 1.75; 95% confidence interval 0.52 to 5.94) and limb defects (five v six, respectively; 0.83; 0.26 to 2.71) gave a sufficient number of defects for individual analyses. NE=not estimated because cells of data were less than three