Background
Methods
Search strategy
Study selection and eligibility criteria
Data extraction and methodological quality evaluation
Data synthesis and meta-analysis
Results
Identification of literature
Characteristics of the included studies and quality assessment
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 |
Publication bias evaluation
Outcomes | Study type | No. of studies | Events/Total | RR, 95%CI, P | Test of Heterogeneity | Tests of Publication Bias | |||
---|---|---|---|---|---|---|---|---|---|
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 |
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 |
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 |
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 |
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 |
Retrospective | 1 | 11/53 | 3/51 | 3.53, [1.04, 11.92], 0.04 | NA | NA | NA | NA |
Outcomes | Study type | No. of studies | Events/Total | RR, 95%CI, P | Test of Heterogeneity | Tests of Publication Bias | |||
---|---|---|---|---|---|---|---|---|---|
Closed | Open | Random | I2 (%) |
P
| Begg’s P | Egger’s P | |||
Cryosurvival rate | Prospective | 4 | 621/724 | 803/895 | 0.98, [0.96, 1.01], 0.29 | 0% | 0.42 | 0.734 | 0.612 |
Retrospective | 3 | 770/805 | 959/1013 | 1.00, [0.97, 1.03], 0.88 | 58% | 0.09 | 1.000 | 0.940 | |
Positive βHCG rate | Prospective | 2 | 115/222 | 114/211 | 0.96, [0.80, 1.14], 0.64 | 0% | 0.77 | 1.000 | NA |
Implantation rate | Prospective | 3 | 160/535 | 196/590 | 0.98, [0.83, 1.15], 0.80 | 0% | 0.93 | 1.000 | 0.798 |
Retrospective | 4 | 333/839 | 444/1071 | 0.97, [0.81, 1.17], 0.76 | 53% | 0.09 | 0.308 | 0.805 | |
Cancellation rate | Retrospective | 2 | 9/321 | 9/267 | 0.75, [0.18, 3.04], 0.69 | 30% | 0.23 | 1.000 | NA |
Clinical pregnancy rate | Prospective | 3 | 134/304 | 226/432 | 0.89, [0.76, 1.05], 0.17 | 0% | 0.91 | 1.000 | 0.613 |
Retrospective | 4 | 280/513 | 374/577 | 0.96, [0.79, 1.17], 0.69 | 61% | 0.05 | 0.734 | 0.790 | |
Ongoing pregnancy rate | Prospective | 3 | 133/319 | 160/369 | 0.98, [0.82, 1.16], 0.79 | 0% | 1.00 | 1.000 | 0.682 |
Retrospective | 2 | 114/312 | 105/258 | 0.96, [0.71, 1.29], 0.77 | 50% | 0.16 | 1.000 | NA | |
Miscarriage rate | Prospective | 2 | 4/93 | 8/94 | 0.60, [0.11, 3.31], 0.56 | 43% | 0.18 | 1.000 | NA |
Retrospective | 3 | 61/276 | 76/360 | 1.07 [0.79, 1.46], 0.66 | 0% | 0.71 | 1.000 | 0.337 | |
Live birth rate | Prospective | 2 | 123/287 | 193/415 | 0.96, [0.81, 1.15], 0.69 | 0% | 0.71 | 1.000 | NA |
Retrospective | 4 | 217/513 | 313/577 | 0.88 [0.71, 1.10], 0.26 | 48% | 0.12 | 0.308 | 0.163 | |
Babies born/ transferred blastocysts | Retrospective | 2 | 114/438 | 124/420 | 0.82 [0.65, 1.02], 0.09 | 0% | 0.48 | 1.000 | NA |
Multiple birth rate | Retrospective | 3 | 30/293 | 21/357 | 0.95 [0.41, 2.24], 0.92 | 52% | 0.13 | 1.000 | 0.831 |