Comparison 1. Continuous support versus usual care ‐ all trials.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Spontaneous vaginal birth	21	14369	Risk Ratio (M‐H, Random, 95% CI)	1.08 [1.04, 1.12]
2 Negative rating of/negative feelings about birth experience	11	11133	Risk Ratio (M‐H, Random, 95% CI)	0.69 [0.59, 0.79]
3 Postpartum depression	2		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
4 Admission to special care nursery	7	8897	Risk Ratio (M‐H, Random, 95% CI)	0.97 [0.76, 1.25]
5 Exclusive or any breastfeeding at any time point, as defined by trial authors	4	5584	Risk Ratio (M‐H, Random, 95% CI)	1.05 [0.96, 1.16]
6 Any analgesia/anaesthesia	15	12433	Risk Ratio (M‐H, Random, 95% CI)	0.90 [0.84, 0.96]
7 Regional analgesia/anaesthesia	9	11444	Risk Ratio (M‐H, Random, 95% CI)	0.93 [0.88, 0.99]
8 Synthetic oxytocin during labour	17	12833	Risk Ratio (M‐H, Random, 95% CI)	0.97 [0.91, 1.03]
9 Labour length	13	5429	Mean Difference (IV, Random, 95% CI)	‐0.69 [‐1.04, ‐0.34]
10 Postpartum report of severe labour pain	4	2456	Risk Ratio (M‐H, Random, 95% CI)	1.00 [0.83, 1.21]
11 Caesarean birth	24	15347	Risk Ratio (M‐H, Random, 95% CI)	0.75 [0.64, 0.88]
12 Instrumental vaginal birth	19	14118	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.85, 0.96]
13 Perineal trauma	4	8120	Risk Ratio (M‐H, Random, 95% CI)	0.97 [0.92, 1.01]
14 Delayed skin‐to‐skin contact, as defined by trial authors	1	212	Risk Ratio (M‐H, Fixed, 95% CI)	0.82 [0.64, 1.04]
15 Delayed initiation of breastfeeding (> 1 hour after birth, or as defined by trial authors)	2		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
16 Time from birth to initiation of breastfeeding	1	585	Mean Difference (IV, Fixed, 95% CI)	‐44.60 [‐47.63, ‐41.57]
17 Restricted mobility during labour, as defined by trial authors	1	6915	Risk Ratio (M‐H, Fixed, 95% CI)	1.02 [1.00, 1.05]
18 Low 5‐minute Apgar score	14	12615	Risk Ratio (M‐H, Fixed, 95% CI)	0.62 [0.46, 0.85]
19 Prolonged neonatal hospital stay	3	1098	Risk Ratio (M‐H, Random, 95% CI)	0.83 [0.42, 1.65]
20 Difficulty mothering	2		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
21 Low postpartum self‐esteem	1	652	Risk Ratio (M‐H, Fixed, 95% CI)	1.00 [0.77, 1.30]