Table 2. GnRH antagonist versus GnRH-a (long protocol and fl are-up) : number of oocyte retrieved
Trial	GnRHantagonist	mean±sd		GnRHagonist		mean±sd	Mean diff	95% CI(fixed)
Long protocol
Cheunget al., 2005	19	5.89±3.02		21		5.62±4.17	0.27	(-2.0, 2.54)
Marciet al., 2005	29	5.6±1.6		26		4.3±2.2	1.3	(0.29, 2.30)
D’Amato Et al., 2004	81	5.56±1.13		40		3.36±1.3	2.2	(1.74, 2.65)
Fixed effects (Mulrow-Oxman) Pooled effect size Z (test WMD + differs from 0) = 9.21 p<0.0001Non-combinability / Cohran Q = 4.75 (df=2) p = 0.09			WMD = 1.98		(1.56 to 2.40)
Flare-up
Akman et al. 2001	20	4.5±1.8		20		5.5±2.0	-1	(-2.18. 0.18)
Malmusiet al., 2005	18	2.5±1.2		24		3.5±1.4	-1	(-1.80, -0.19)
Schmidtet al., 2005	13	8.9±0.9		11		9.0±1.2	-0.1	(-0.94, 0.74)
Fixed effects (Mulrow-Oxman) pooled effect size Z (test WMD + differs from 0) = -2.51 p = 0.0118Non-combinability / Cohran Q = 2.65 (df=2) p = 0.26			WMD = -0.67		(-1.19 to -0.15)