Comparison 1. X‐ray pelvimetry versus no X‐ray pelvimetry.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1.1 Caesarean section	5	1159	Risk Ratio (M‐H, Fixed, 95% CI)	1.34 [1.19, 1.52]
1.1.1 No previous caesarean section	3	769	Risk Ratio (M‐H, Fixed, 95% CI)	1.24 [1.02, 1.52]
1.1.2 Previous caesarean section	2	390	Risk Ratio (M‐H, Fixed, 95% CI)	1.45 [1.26, 1.67]
1.2 Perinatal mortality	5	1159	Risk Ratio (M‐H, Fixed, 95% CI)	0.53 [0.19, 1.45]
1.2.1 No previous caesarean section	3	769	Risk Ratio (M‐H, Fixed, 95% CI)	0.64 [0.21, 1.90]
1.2.2 Previous caesarean section	2	390	Risk Ratio (M‐H, Fixed, 95% CI)	0.19 [0.01, 3.91]
1.3 Puerperal pyrexia	1	288	Risk Ratio (M‐H, Fixed, 95% CI)	0.80 [0.22, 2.92]
1.3.1 No previous caesarean section	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	Not estimable
1.3.2 Previous caesarean section	1	288	Risk Ratio (M‐H, Fixed, 95% CI)	0.80 [0.22, 2.92]
1.4 Wound sepsis	1	288	Risk Ratio (M‐H, Fixed, 95% CI)	0.83 [0.26, 2.67]
1.4.1 No previous caesarean section	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	Not estimable
1.4.2 Previous caesarean section	1	288	Risk Ratio (M‐H, Fixed, 95% CI)	0.83 [0.26, 2.67]
1.5 Blood transfusion	1	288	Risk Ratio (M‐H, Fixed, 95% CI)	1.00 [0.39, 2.59]
1.5.1 No previous caesarean section	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	Not estimable
1.5.2 Previous caesarean section	1	288	Risk Ratio (M‐H, Fixed, 95% CI)	1.00 [0.39, 2.59]
1.6 Scar dehiscence	2	390	Risk Ratio (M‐H, Fixed, 95% CI)	0.59 [0.14, 2.46]
1.7 Perinatal asphyxia	1	305	Risk Ratio (M‐H, Fixed, 95% CI)	0.66 [0.39, 1.10]
1.8 Admission to special care baby units	1	288	Risk Ratio (M‐H, Fixed, 95% CI)	0.20 [0.01, 4.13]
1.8.1 No previous caesarean section	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	Not estimable
1.8.2 Previous caesarean section	1	288	Risk Ratio (M‐H, Fixed, 95% CI)	0.20 [0.01, 4.13]