Comparison 1. Planned caesarean section versus planned vaginal birth.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Maternal death or serious maternal morbidity	2	2844	Risk Ratio (M‐H, Fixed, 95% CI)	0.86 [0.67, 1.11]
2 Perinatal or neonatal death or serious neonatal morbidity	1	5565	Risk Ratio (M‐H, Fixed, 95% CI)	1.15 [0.80, 1.67]
3 Perinatal or infant death or disability in childhood	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Perinatal or neonatal death	2	5685	Risk Ratio (M‐H, Fixed, 95% CI)	1.41 [0.76, 2.62]
5 Serious neonatal morbidity	2	5644	Risk Ratio (M‐H, Fixed, 95% CI)	1.03 [0.65, 1.64]
6 Apgar score less than eight at five minutes	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	1.22 [0.18, 8.39]
7 Apgar score less than four at five minutes	2	5644	Risk Ratio (M‐H, Fixed, 95% CI)	0.29 [0.06, 1.38]
8 Neonatal encephalopathy, as defined by trial authors	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
9 Birth trauma, as defined by trial authors	2	5644	Risk Ratio (M‐H, Fixed, 95% CI)	0.57 [0.17, 1.95]
10 Nerve palsy (including brachial plexus injury)	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
11 Subdural or intracerebral haemorrhage	2	5644	Risk Ratio (M‐H, Fixed, 95% CI)	3.01 [0.31, 28.89]
12 Intraventricular haemorrhage: grade III or IV	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
13 Cystic periventricular leukomalacia	1	5524	Risk Ratio (M‐H, Fixed, 95% CI)	5.01 [0.24, 104.33]
14 Neonatal sepsis up to 72 hours	1	5524	Risk Ratio (M‐H, Fixed, 95% CI)	0.50 [0.05, 5.52]
15 Necrotising enterocolitis	1	5524	Risk Ratio (M‐H, Fixed, 95% CI)	0.33 [0.03, 3.21]
16 Assisted ventilation for 24 hours or more	1	5524	Risk Ratio (M‐H, Fixed, 95% CI)	1.59 [0.87, 2.91]
17 Short‐term maternal outcomes: caesarean section	2	2845	Risk Ratio (M‐H, Random, 95% CI)	4.77 [0.76, 30.00]
18 Short‐term maternal outcomes: mortality	2	2844	Risk Ratio (M‐H, Fixed, 95% CI)	1.0 [0.06, 15.97]
19 Short‐term maternal outcomes: serious maternal morbidity	2	2842	Risk Ratio (M‐H, Fixed, 95% CI)	0.86 [0.67, 1.11]
20 Short‐term maternal outcomes: thromboembolism requiring anticoagulant therapy	1	2782	Risk Ratio (M‐H, Fixed, 95% CI)	2.5 [0.49, 12.86]
21 Short‐term maternal outcomes: wound infection	1	2782	Risk Ratio (M‐H, Fixed, 95% CI)	1.5 [0.83, 2.71]
22 Short‐term maternal outcomes: systemic infection	1	2782	Risk Ratio (M‐H, Fixed, 95% CI)	1.39 [0.76, 2.53]
23 Short‐term maternal outcomes: disseminated intravascular coagulation	1	2782	Risk Ratio (M‐H, Fixed, 95% CI)	5.0 [0.24, 104.05]
24 Short‐term maternal outcomes: amniotic fluid embolism	1	2782	Risk Ratio (M‐H, Fixed, 95% CI)	3.0 [0.12, 73.58]
25 Short‐term maternal outcomes: postpartum haemorrhage	1	2782	Risk Ratio (M‐H, Fixed, 95% CI)	0.78 [0.59, 1.02]
26 Short‐term maternal outcomes: blood transfusion	1	2782	Risk Ratio (M‐H, Fixed, 95% CI)	0.88 [0.64, 1.21]
27 Longer‐term maternal outcomes: failure to breastfeed	1	2570	Risk Ratio (M‐H, Fixed, 95% CI)	1.14 [0.95, 1.38]
28 Longer‐term maternal outcomes: urinary incontinence	1	2570	Risk Ratio (M‐H, Fixed, 95% CI)	0.87 [0.64, 1.18]
29 Longer‐term maternal outcomes: flatus incontinence	1	2570	Risk Ratio (M‐H, Fixed, 95% CI)	0.92 [0.77, 1.09]
30 Longer‐term maternal outcomes: faecal incontinence	1	2570	Risk Ratio (M‐H, Fixed, 95% CI)	1.02 [0.69, 1.51]
31 Longer‐term maternal outcomes: postnatal depression, as defined by trial authors (EPDS > 12)	1	2570	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.78, 1.14]