Comparison 1. Letrozole compared to placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1.1 Live birth rate	1		Odds Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.2 Ovarian hyperstimulation syndrome rate	2	167	Risk Difference (M‐H, Fixed, 95% CI)	0.00 [‐0.05, 0.05]
1.3 Clinical pregnancy rate	2	167	Odds Ratio (M‐H, Fixed, 95% CI)	2.88 [1.08, 7.66]
1.4 Miscarriage rate per woman	2	167	Odds Ratio (M‐H, Fixed, 95% CI)	1.60 [0.26, 9.89]
1.5 Miscarriage rate per pregnancy	1		Odds Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.6 Multiple pregnancy rate	1		Odds Ratio (M‐H, Fixed, 95% CI)	Totals not selected