Table 4.
Results of univariable and multivariable logistic regression analyses performed to clarify the factors that influence live birth from day 7 blastocysts after single vitrified-warmed blastocyst transfer
| Univariate analysis | Multivariate analysis | |||||
|---|---|---|---|---|---|---|
| OR ratio | 95% CI | P value | aOR ratio | 95% CI | P value | |
| Female age | 0.836 | 0.801–0.872 | < .0001 | 0.807 | 0.757–0.857 | < .0001 |
| Male age | 0.936 | 0.906–0.966 | < .0001 | - | - | 0.269 |
| No. of previous ER | 0.919 | 0.864–0.970 | 0.004 | - | - | 0.671 |
| No. of previous ET | - | - | 0.15 | - | - | - |
| Insemination methods (reference: C-IVF) | - | - | 0.694 | - | - | - |
| Etiology of infertility (reference: unknown) | - | - | 0.494 | - | - | - |
| HRT or OVT (reference: OVT) | - | - | 0.514 | - | - | - |
| Confirmed blastulation time | 1.017 | 1.00–1.030 | 0.015 | - | - | 0.19 |
| Expansion time (blastulation to expanding blastocyst) | 0.981 | 0.968–0.994 | 0.006 | 0.949 | 0.896–1.006 | 0.078 |
| Blastocyst diameter | 1.136 | 1.070–1.206 | < .0001 | 1.136 | 1.056–1.222 | 0.001 |
| Blastocyst morphology grading | - | - | 0.147 | |||
| Top quality | - | - | - | - | ||
| Good quality | Reference | - | - | - | - | - |
| Poor quality | 0.166 | 0.039–0.707 | 0.017 | - | - | - |
aOR adjusted odds ratio, CI confidence interval, ER egg retrievals, ET embryo transfer, HRT hormone replacement treatment, OR odds ratio, OVT embryo transfer after ovulation, SVBT single vitrified-warmed blastocyst transfer