Comparison 3. Labour induction versus expectant management (subgroup analysis by parity).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
3.1 Perinatal death	22	18795	Risk Ratio (M‐H, Fixed, 95% CI)	0.31 [0.15, 0.64]
3.1.1 Nulliparous	3	8229	Risk Ratio (M‐H, Fixed, 95% CI)	0.26 [0.06, 1.05]
3.1.2 Mixed (primi‐ and multiparous)	18	10470	Risk Ratio (M‐H, Fixed, 95% CI)	0.33 [0.14, 0.78]
3.1.3 Not stated	2	96	Risk Ratio (M‐H, Fixed, 95% CI)	Not estimable
3.2 Stillbirth	22	18795	Risk Ratio (M‐H, Fixed, 95% CI)	0.30 [0.12, 0.74]
3.2.1 Nulliparous	3	8229	Risk Ratio (M‐H, Fixed, 95% CI)	0.23 [0.04, 1.35]
3.2.2 Mixed (primi‐ and multiparous)	18	10470	Risk Ratio (M‐H, Fixed, 95% CI)	0.33 [0.12, 0.97]
3.2.3 Not stated	2	96	Risk Ratio (M‐H, Fixed, 95% CI)	Not estimable
3.3 Admission to neonatal intensive care unit	17	17826	Risk Ratio (M‐H, Fixed, 95% CI)	0.88 [0.80, 0.96]
3.3.1 Nulliparous	5	7312	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.79, 1.03]
3.3.2 Mixed (primi‐ and multiparous)	10	10200	Risk Ratio (M‐H, Fixed, 95% CI)	0.83 [0.73, 0.95]
3.3.3 Not stated	2	314	Risk Ratio (M‐H, Fixed, 95% CI)	1.20 [0.70, 2.06]
3.4 Caesarean section	31	21030	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.85, 0.95]
3.4.1 Nulliparous	6	7543	Risk Ratio (M‐H, Fixed, 95% CI)	0.89 [0.81, 0.97]
3.4.2 Mixed (primi‐ and multiparous)	20	12877	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.83, 0.97]
3.4.3 Not stated	5	610	Risk Ratio (M‐H, Fixed, 95% CI)	1.12 [0.81, 1.56]
3.5 Operative vaginal birth (forceps or ventouse)	22	18584	Risk Ratio (M‐H, Fixed, 95% CI)	1.03 [0.96, 1.10]
3.5.1 Nulliparous	4	7151	Risk Ratio (M‐H, Fixed, 95% CI)	0.96 [0.84, 1.09]
3.5.2 Mixed (primi‐ and multiparous)	15	11224	Risk Ratio (M‐H, Fixed, 95% CI)	1.06 [0.97, 1.15]
3.5.3 Not stated	3	209	Risk Ratio (M‐H, Fixed, 95% CI)	1.09 [0.58, 2.06]
3.6 Perineal trauma (severe perineal tear)	5	11589	Risk Ratio (M‐H, Fixed, 95% CI)	1.04 [0.85, 1.26]
3.6.1 Nulliparous	2	6714	Risk Ratio (M‐H, Fixed, 95% CI)	1.18 [0.90, 1.55]
3.6.2 Mixed (primi‐ and multiparous)	3	4875	Risk Ratio (M‐H, Fixed, 95% CI)	0.89 [0.66, 1.19]