Comparison 2. Cerclage versus vaginal progesterone.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 All perinatal losses	2	108	Risk Ratio (M‐H, Fixed, 95% CI)	0.94 [0.36, 2.48]
2 Serious neonatal morbidity	2	120	Risk Ratio (M‐H, Random, 95% CI)	0.49 [0.05, 4.52]
3 Baby discharged home healthy	2	119	Risk Ratio (M‐H, Fixed, 95% CI)	0.97 [0.88, 1.07]
4 Stillbirths	2	128	Risk Ratio (M‐H, Fixed, 95% CI)	2.7 [0.12, 62.17]
5 Neonatal deaths before discharge	2	120	Risk Ratio (M‐H, Fixed, 95% CI)	2.18 [0.34, 13.86]
6 Miscarriages	2	128	Risk Ratio (M‐H, Fixed, 95% CI)	0.58 [0.17, 2.01]
7 Preterm birth before 37 completed weeks	2	128	Risk Ratio (M‐H, Fixed, 95% CI)	1.16 [0.64, 2.08]
8 Preterm birth before 34 completed weeks	2	128	Risk Ratio (M‐H, Fixed, 95% CI)	1.01 [0.51, 2.01]
9 Preterm birth before 28 completed weeks	2	128	Risk Ratio (M‐H, Fixed, 95% CI)	0.92 [0.37, 2.27]
10 Serious intracranial pathology (IVH or periventricular leucomalacia)	2	128	Risk Ratio (M‐H, Fixed, 95% CI)	0.96 [0.17, 5.28]
11 Serious respiratory morbidity (RDS or oxygen dependency after 28 days of life)	2	128	Risk Ratio (M‐H, Random, 95% CI)	0.48 [0.04, 6.41]
12 Necrotising enterocolitis	1	92	Risk Ratio (M‐H, Fixed, 95% CI)	3.0 [0.13, 71.78]
13 Retinopathy of prematurity	1	92	Risk Ratio (M‐H, Fixed, 95% CI)	1.0 [0.06, 15.51]
14 Apgar < 7 at 5 minutes	2	120	Risk Ratio (M‐H, Fixed, 95% CI)	1.90 [0.37, 9.80]
15 Caesarean section (elective and emergency)	2	128	Risk Ratio (M‐H, Random, 95% CI)	0.67 [0.18, 2.47]
16 Maternal infection requiring intervention(antibiotics or delivery)	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
17 Maternal side effects (vaginal discharge, bleeding, pyrexia not requiring antibiotics)	1	92	Risk Ratio (M‐H, Fixed, 95% CI)	3.0 [0.32, 27.79]
18 Pyrexia	1	92	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
19 Any intravenous, oral or combined tocolysis (not prespecified)	1	92	Risk Ratio (M‐H, Fixed, 95% CI)	3.75 [1.93, 7.29]
20 PPROM (not prespecified)	1	92	Risk Ratio (M‐H, Fixed, 95% CI)	8.0 [1.04, 61.42]
21 Chorioamnionitis (not prespecified)	2	128	Risk Ratio (M‐H, Random, 95% CI)	1.53 [0.10, 23.61]