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Table 1 Basic information of the included studies comparing open versus closed vitrification on oocytes and embryos

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

Authors, Country (Year)

Study period

Study type

Participant

No. of cycles and oocytes/embryos thawed

Outcomes

Funding

Overall quality assessment

Study (Closed)

Control (Open)

Kuwayama et al. (2005), Japan

NM

Prospective

Embryo

88 embryos

227 embryos

CsR; CPR; LBR

None declared

Moderate risk

Chen et al. (2013), China

2010.04–2012.05

Retrospective

Embryo

226 cycles; 308 embryos

106 cycles; 150 embryos

CsR; IR; CaR; CPR; OPR; MR; LBR; BB; MR

Yes

Low risk

Panagiotidis et al. (2013), Greece

2009.06–2011.09

Prospective

Embryo

224 cycles; 513 embryos

208 cycles; 492 embryos

CsR; PβR; IR; CaR; CPR; OPR; MR; LBR; BB; MR

None declared

Low risk

Desai et al. (2013), America

2011.01–2012.08

Retrospective

Embryo

95 cycles; 184 embryos

161 cycles; 302 embryos

CsR; IR; CaR; CPR; OPR; MR; LBR; BB; MR

None declared

Low risk

Hashimoto et al. (2013), Japan

2011.07–2012.09

Prospective

Embryo

100 embryos

163 embryos

CsR; IR; OPR

Yes

Moderate risk

Roy et al., Australia (2014)

NM

Prospective

Embryo

23 embryos

13 embryos

CsR; OPR

Yes

Serious risk

Iwahata et al. (2015), Japan

2011.11–2013.12

Retrospective

Embryo

302 cycles; 313 embryos

539 cycles; 561 embryos

CsR; IR; CPR; MR; LBR; MR

None declared

Low risk

Paffoni et al. (2011), Italy

2007.06–2009.04

Retrospective

Oocyte/embryo

51 cycles; 261 MII oocytes/87 embryos

53 cycles; 268 MII oocytes/116 embryos

CsR; IR; FR; ClR; GQER; CPR; LBR

None declared

Low risk

Papatheodorou et al. (2013), Greece

2007.02–2010.12

Prospective

Oocyte

598 MII oocytes

608 MII oocytes

CsR; FR; ClR; GQER; PβR; IR; CPR; MR; OPR; LBR

None declared

Low risk

De Munck et al. (2016), Belgium

2014.01–2015.07

Prospective

Oocyte/embryo

253 MII oocytes

257 MII oocytes

CsR; FR; GQER; PβR; MR; OPR

No funding

Low risk

Gook et al. (2016), Australia

2012.06–2015.06

Prospective

Oocyte

39 MII oocytes

79 MII oocytes

CsR

None declared

Serious risk

Sarandi et al. (2016), France

2014.11–2015.05

Prospective

Oocyte

96 GV/MI oocytes

118 GV/MI oocytes

CsR

None declared

Serious risk

  1. Notes: The ROBINS-I tool was used for quality assessment of observational studies. BB babies born per transferred blastocysts, CaR cancellation rate, CBS Cryo Bio System, ClR cleavage rate, CPR clinical pregnancy rate, CsR cryosurvival rate, FR fertilization rate, GQER good quality embryo rate, HSV high security straws, IR implantation rate, LBR: live birth rate, MBR multiple birth rate, MR miscarriage rate, NM not mentioned, OPR ongoing pregnancy rate, PβR positive βHCG rate