Open versus closed vitrification system of human oocytes and embryos: a systematic review and meta-analysis of embryologic and clinical outcomes

Table 2 Results of meta-analyses and test of publication bias on oocytes

Outcomes	Study type	No. of studies	Events/Total		RR, 95%CI, P	Test of Heterogeneity		Tests of Publication Bias
Outcomes	Study type	No. of studies	Closed	Open	Random	I² (%)	P	Begg’s P	Egger’s P
Cryosurvival rate	Prospective	4	830/986	967/1062	0.91, [0.80, 1.03], 0.14	91%	0.00	1.000	0.921
Cryosurvival rate	Retrospective	1	222/268	151/261	1.43, [1.27, 1.61], < 0.01	NA	NA	NA	NA
Fertilization rate	Prospective	2	585/733	594/784	1.02, [0.83, 1.24], 0.88	92%	0.00	1.000	NA
Fertilization rate	Retrospective	1	116/159	87/151	1.27, [1.07, 1.50], < 0.01	NA	NA	NA	NA
Good quality embryo rate	Prospective	2	229/561	240/566	0.97, [0.84, 1.11], 0.62	0%	0.96	1.000	NA
Good quality embryo rate	Retrospective	1	62/112	30/87	1.61, [1.15, 2.24], < 0.01	NA	NA	NA	NA
Positive βHCG rate	Prospective	2	45/109	47/125	1.09, [0.75, 1.59], 0.64	22%	0.26	1.000	NA
Miscarriage rate	Prospective	2	4/38	8/39	0.59, [0.20, 1.79], 0.35	0%	0.84	1.000	NA
Ongoing pregnancy rate	Prospective	2	38/125	27/109	1.24, [0.81, 1.89], 0.32	0%	0.45	1.000	NA
Clinical pregnancy rate	Prospective	1	27/75	21/75	1.29, [0.80, 2.06], 0.30	NA	NA	NA	NA
Clinical pregnancy rate	Retrospective	1	14/53	4/51	3.37, [1.19, 9.55], 0.02	NA	NA	NA	NA
Live birth rate	Prospective	1	27/75	18/75	1.50, [0.91, 2.48], 0.11	NA	NA	NA	NA
Live birth rate	Retrospective	1	11/53	3/51	3.53, [1.04, 11.92], 0.04	NA	NA	NA	NA

ISSN: 1477-7827