Comparison 1. Human chorionic gonadotrophin versus control.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 1st trimester miscarriage	5	302	Risk Ratio (M‐H, Fixed, 95% CI)	0.51 [0.32, 0.81]
2 Miscarriage rate excluding 2 studies	3	254	Risk Ratio (M‐H, Fixed, 95% CI)	0.74 [0.44, 1.23]
3 Threatened miscarriage	2	118	Risk Ratio (M‐H, Fixed, 95% CI)	0.52 [0.15, 1.82]
4 Congenital defects	3	146	Risk Ratio (M‐H, Fixed, 95% CI)	1.05 [0.16, 7.12]