Comparison 3. Cerclage versus intramuscular progesterone.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 All perinatal losses	1	79	Risk Ratio (M‐H, Fixed, 95% CI)	1.12 [0.58, 2.16]
2 Serious neonatal morbidity	1	79	Risk Ratio (M‐H, Fixed, 95% CI)	1.13 [0.47, 2.74]
3 Baby discharged home healthy	1	79	Risk Ratio (M‐H, Fixed, 95% CI)	1.17 [0.82, 1.67]
4 Stillbirths	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Neonatal deaths before discharge	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6 Miscarriages	1	79	Risk Ratio (M‐H, Fixed, 95% CI)	1.47 [0.38, 5.73]
7 Preterm birth before 37 completed weeks	1	79	Risk Ratio (M‐H, Fixed, 95% CI)	0.88 [0.60, 1.30]
8 Preterm birth before 34 completed weeks	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
9 Preterm birth before 28 completed weeks	1	79	Risk Ratio (M‐H, Fixed, 95% CI)	1.26 [0.53, 2.97]
10 Serious intracranial pathology (IVH or periventricular leucomalacia)	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
11 Serious respiratory morbidity (RDS or oxygen dependency after 28 days of life)	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
12 Necrotising enterocolitis	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
13 Retinopathy of prematurity	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
14 Apgar < 7 at 5 minutes	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
15 Caesarean section (elective and emergency)	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
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)	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
18 Pyrexia	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
19 PPROM (not prespecified)	1	79	Risk Ratio (M‐H, Fixed, 95% CI)	0.88 [0.47, 1.65]
20 Chorioamnionitis (not prespecified)	1	79	Risk Ratio (M‐H, Fixed, 95% CI)	1.32 [0.61, 2.88]