Comparison 3. Opioid versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
3.1 Adequate pain relief as reported by the woman	5	299	Risk Ratio (M‐H, Fixed, 95% CI)	1.26 [0.99, 1.61]
3.1.1 Codeine 60 mg versus placebo	5	252	Risk Ratio (M‐H, Fixed, 95% CI)	1.33 [1.01, 1.76]
3.1.2 Codeine 120 mg versus placebo	1	47	Risk Ratio (M‐H, Fixed, 95% CI)	1.03 [0.65, 1.64]
3.2 Need for additional pain relief	3	273	Risk Ratio (M‐H, Fixed, 95% CI)	0.48 [0.28, 0.82]
3.2.1 Codeine 60 mg versus placebo	3	173	Risk Ratio (M‐H, Fixed, 95% CI)	0.49 [0.24, 1.02]
3.2.2 Codeine 120 mg versus placebo	1	47	Risk Ratio (M‐H, Fixed, 95% CI)	0.17 [0.02, 1.52]
3.2.3 Nalbuphine versus placebo	1	53	Risk Ratio (M‐H, Fixed, 95% CI)	0.59 [0.25, 1.36]
3.3 Maternal adverse events	3	188	Risk Ratio (M‐H, Fixed, 95% CI)	1.59 [0.99, 2.55]
3.3.1 Codeine 60 mg versus placebo	3	141	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.54, 1.67]
3.3.2 Codeine 120 mg versus placebo	1	47	Risk Ratio (M‐H, Fixed, 95% CI)	4.65 [1.66, 13.00]