Fresh embryo transfer | Frozen-thawed embryo transfer | ||||||||
---|---|---|---|---|---|---|---|---|---|
CP | EP | EP rate | P value | CP | EP | EP rate | P value | ||
Total No. | 27,600 | 672 | 2.43% | 14,762 | 417 | 2.82% | |||
Age (year) | |||||||||
< 35 | 22,914 | 557 | 2.43% | 0.925 | 12,064 | 342 | 2.83% | 0.876 | |
≥ 35 | 4686 | 115 | 2.45% | 2698 | 75 | 2.78% | |||
BMI (kg/m2) | |||||||||
< 18.5 | 1703 | 56 | 3.29% | 883 | 24 | 2.72% | |||
18.5–23.9 | 16,840 | 386 | 2.29% | 0.029 | 8840 | 244 | 2.76% | 0.782 | |
≥ 24 | 9057 | 230 | 2.54% | 5039 | 149 | 2.96% | |||
Infertility type | |||||||||
Primary | 15,265 | 343 | 2.25% | 0.024 | 6779 | 173 | 2.56% | 0.065 | |
Secondary | 12,335 | 329 | 2.67% | 7983 | 244 | 3.06% | |||
Tubal factor existed | |||||||||
Yes | 11,075 | 402 | 3.63% | < 0.001 | 5902 | 207 | 3.51% | < 0.001 | |
No | 16,525 | 270 | 1.63% | 8860 | 210 | 2.37% | |||
Ovarian stimulation protocol | |||||||||
Agonist | 27,045 | 658 | 2.43% | / | |||||
Antagonist | 250 | 5 | 2.00% | 0.763 | / | ||||
Others* | 305 | 9 | 2.95% | / | |||||
Peak Estrogen level (pg/ml) | |||||||||
< 2500 | 9806 | 216 | 2.20% | / | |||||
[2500–5000) | 12,092 | 286 | 2.37% | 0.011 | / | ||||
[5000–7500) | 4104 | 116 | 2.83% | / | |||||
≥ 7500 | 1598 | 54 | 3.38% | / | |||||
Endometrial preparation Protocol | |||||||||
Natural cycle | / | 5204 | 133 | 2.56% | 0.145 | ||||
Artificial cycle | / | 9558 | 284 | 2.97% | |||||
Endometrial thickness (mm)+ | |||||||||
Thin (< 7) | 385 | 21 | 5.45% | 357 | 23 | 6.44% | |||
Medium (8–13) | 17,901 | 480 | 2.68% | < 0.001 | 7624 | 238 | 3.12% | < 0.001 | |
Thick (≥ 14) | 8420 | 147 | 1.75% | 607 | 9 | 1.48% | |||
Type of embryos | |||||||||
Cleavage | 22,222 | 582 | 2.62% | < 0.001 | 6503 | 241 | 3.71% | < 0.001 | |
Blastocyst | 5378 | 90 | 1.67% | 8259 | 176 | 2.13% | |||
No. of embryos transferred | |||||||||
1 | 6793 | 125 | 1.84% | 6343 | 139 | 2.19% | |||
2 | 20,328 | 537 | 2.64% | 0.001 | 7448 | 229 | 3.07% | < 0.001 | |
3 | 479 | 10 | 2.09% | 971 | 49 | 5.05% |