Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment and unclear blinding of outcome assessment).
A Cochrane review included 28 studies with a total of 4181 women (none of whom were breastfeeding). Great variety of non-steroidal anti-inflammatory drugs (NSAID) and different doses were used (ibuprofen, diclofenac, ketoprofen, diflunisal, flurbiprofen, meclofenamate, aceclofenat, dipyrone, etodolac, aspirin). Compared to women who received a placebo, more women who received a single dose NSAID achieved adequate pain relief at four hours (low-quality evidence) and at six hours, and were also less likely to need additional analgesia (table ). NSAIDs were more effective than paracetamol for adequate pain relief at four hours (RR 1.54, 95% CI 1.07 to 2.22; 3 studies, n=342) but not at six hours post-administration. There was no difference in the need for additional analgesia between the two groups at four hours in one study, but women in the NSAID group were less likely to need any additional analgesia at six hours.
| Outcome | Relative effect (95% CI) | Assumed risk - Placebo | Corresponding risk - NSAID (95% CI) | No of participants (studies) |
|---|---|---|---|---|
| No of women with adequate pain relief, follow-up: 4 hours | RR 1.91 (1.64 to 2.23) | 284 / 1000 | 543 / 1000 (466 to 634) | 1573 (10) |
| No of women with adequate pain relief, follow-up: 6 hours | RR 1.92 (1.69 to 2.17) | 321 / 1000 | 615 / 1000 (542 to 696) | 2079 (17) |
| No of women who received additional analgesia, follow-up: 4 hours | RR 0.39 (0.26 to 0.58) | 305 / 1000 | 119 / 1000 (79 to 177) | 486 (4) |
| No of women who received additional analgesia, follow-up: 6 hours | RR 0.32 (0.26 to 0.40) | 438 / 1000 | 140 / 1000 (114 to 175) | 1012 (10) |
| No of women experiencing adverse effects, follow-up: 6 hours | RR 1.38 (0.71 to 2.70) | 22 / 1000 | 31 / 1000 (16 to 60) | 1388 (13) |
Date of latest search: 31 March 2016