Comparison 4.

Vaginal progesterone versus no treatment: multiple pregnancy and short cervix

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Preterm birth less than 34 weeks	1	224	Risk Ratio (M‐H, Fixed, 95% CI)	0.67 [0.49, 0.91]
2 Prelabour rupture of the membranes	1	224	Risk Ratio (M‐H, Fixed, 95% CI)	0.47 [0.12, 1.82]
3 Preterm birth less than 28 weeks	1	224	Risk Ratio (M‐H, Fixed, 95% CI)	0.37 [0.07, 1.88]
4 Caesarean section	1	224	Risk Ratio (M‐H, Fixed, 95% CI)	0.99 [0.89, 1.11]
5 Infant birthweight less than 2500 g	1	439	Risk Ratio (M‐H, Fixed, 95% CI)	0.94 [0.85, 1.04]
6 Respiratory distress syndrome	1	439	Risk Ratio (M‐H, Fixed, 95% CI)	0.68 [0.55, 0.84]
7 Use of mechanical ventilation	1	439	Risk Ratio (M‐H, Fixed, 95% CI)	0.47 [0.32, 0.69]
8 Admission to NICU	1	439	Risk Ratio (M‐H, Fixed, 95% CI)	0.91 [0.82, 1.01]