Comparison 6. Nulliparous versus multiparous (subgroup analysis).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Use of pharmacological pain relief/anaesthesia	5	2314	Risk Ratio (M‐H, Random, 95% CI)	0.96 [0.83, 1.11]
1.1 Nulliparous women	5	2247	Risk Ratio (M‐H, Random, 95% CI)	0.94 [0.80, 1.10]
1.2 Multiparous women	1	67	Risk Ratio (M‐H, Random, 95% CI)	1.12 [0.78, 1.62]
2 Spontaneous vaginal birth	5	2309	Risk Ratio (M‐H, Random, 95% CI)	0.99 [0.89, 1.09]
2.1 Nulliparous women	5	2242	Risk Ratio (M‐H, Random, 95% CI)	0.99 [0.88, 1.11]
2.2 Multiparous women	1	67	Risk Ratio (M‐H, Random, 95% CI)	1.01 [0.77, 1.33]