A Cochrane review included 15 trials involving a total of 1754 pregnant women. Erythromycin and clindamycin were associated with improved microbiological cure compared to placebo . There were no trials comparing azithromycin to placebo. However, azithromycin was at least as effective as erythromycin . Azithromycin and clindamycin appear to result in fewer side effects than erythromycin.
| Outcome: Microbiological cure | Relative effect (95% CI) | Risk with control -Placebo | Risk with intervention -Antibiotics (95% CI) | № of participants (studies) |
|---|---|---|---|---|
| Erythromycin | RR 2.64 (1.60 to 4.38) | 344 per 1000 | 908 per 1000 (550 to 1000) | 495 (2) |
| Clindamycin | RR 4.08 (2.35 to 7.08) | 227 per 1000 | 927 per 1000 (534 to 1000) | 85 (1) |
| Amoxicillin | RR 2.00 (0.59 to 6.79) | 333 per 1000 | 667 per 1000 (197 to 1000) | 15 (1) |
| Outcome: Microbiological cure | Relative effect (95% CI) | Risk with control - Erythromycin | Risk with intervention -another antibiotics (95% CI) | № of participants (studies) |
|---|---|---|---|---|
| Azithromycin | RR 1.11 (1.00 to 1.23) RCTs) | 825 per 1000 | 916 per 1000 (825 to 1000) | 374 (6) |
| Clindamycin | RR 1.06 (0.97 to 1.15) | 905 per 1000 | 959 per 1000 (878 to 1000) | 173 (2) |
| Amoxicillin | RR 0.97 (0.93 to 1.01) | 954 per 1000 | 925 per 1000 (887 to 963) | 466 (4) |
Comment: The quality of evidence is downgraded by study limitations and upgraded by large magnitude of effect.