Comparison 7. < 4 sessions versus 4 or more sessions (subgroup analysis).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Use of pharmacological pain relief/anaesthesia	7	2876	Risk Ratio (M‐H, Random, 95% CI)	0.74 [0.57, 0.97]
1.1 < 4 sessions	3	2189	Risk Ratio (M‐H, Random, 95% CI)	0.97 [0.86, 1.09]
1.2 4 or more sessions	4	687	Risk Ratio (M‐H, Random, 95% CI)	0.52 [0.27, 1.01]
2 Spontaneous vaginal birth	6	2361	Risk Ratio (M‐H, Random, 95% CI)	1.12 [0.96, 1.32]
2.1 < 4 sessions	3	2194	Risk Ratio (M‐H, Random, 95% CI)	0.99 [0.93, 1.06]
2.2 4 or more sessions	3	167	Risk Ratio (M‐H, Random, 95% CI)	1.59 [1.06, 2.38]