Table 2 Baseline characteristics between single good-quality blastocyst transfer and transfer of a second poor-quality blastocyst with a good-quality blastocyst before and after PS matching
Variable | Before matching | After matching | ||||
|---|---|---|---|---|---|---|
SET- GQE (N = 523) | DET- GQE + PQE (N = 316) | P value | SET- GQE (N = 283) | DET- GQE + PQE (N = 283) | P value | |
Maternal age (y) | 32.4 ± 4.2 | 33.4 ± 4.4 | 0.001 | 33.2 ± 4.3 | 33.1 ± 4.3 | 0.937 |
Paternal age (y) | 34.1 ± 5.2 | 35.1 ± 5.5 | 0.008 | 34.9 ± 5.2 | 34.9 ± 5.5 | 0.994 |
BMI (kg/m2) | 22.3 ± 3.3 | 22.8 ± 3.3 | 0.056 | 22.5 ± 3.3 | 22.7 ± 3.3 | 0.498 |
Duration of infertility (y) | 3.0 ± 2.3 | 3.2 ± 2.3 | 0.285 | 3.1 ± 2.4 | 3.1 ± 2.3 | 0.990 |
Type of infertility n (%) | ||||||
 Primary | 343 (65.6) | 202 (63.9) | 0.626 | 173 (61.1) | 185 (65.4) | 0.295 |
 Secondary | 180 (34.4) | 114 (36.1) | 110 (38.9) | 98 (34.6) | ||
 Basal FSH (IU/L) | 8.5 ± 4.8 | 9.2 ± 5.4 | 0.076 | 8.8 ± 5.6 | 9.2 ± 5.5 | 0.461 |
 AMH | 4.7 ± 3.8 | 3.8 ± 3.0 | 0.000 | 4.1 ± 3.1 | 3.9 ± 3.1 | 0.347 |
 AFC | 15.5 ± 7.4 | 13.9 ± 6.7 | 0.001 | 14.1 ± 6.9 | 14.1 ± 6.8 | 0.936 |
Stimulation Protocol n (%) | ||||||
 Agonist | 195 (37.3) | 131 (41.5) | 0.041 | 120 (42.4) | 116 (41.0) | 0.774 |
 Antagonist | 305 (58.3) | 161 (50.9) | 147 (51.9) | 147 (51.9) | ||
 Others | 23 (4.4) | 24 (7.6) | 16 (5.7) | 20 (7.1) | ||
 Total Gn (IU) | 2532.8 ± 975.0 | 2789.2 ± 1008.5 | 0.000 | 2716.5 ± 970.0 | 2736.0 ± 979.9 | 0.811 |
 Duration of Gn (day) | 10.1 ± 1.8 | 10.2 ± 2.3 | 0.504 | 10.4 ± 1.8 | 10.2 ± 2.3 | 0.488 |
Fertilization method n (%) | ||||||
 IVF | 352 (67.3) | 217 (68.7) | 0.681 | 184 (65.0) | 193 (68.2) | 0.422 |
 ICSI | 171 (32.7) | 99 (31.3) | 99 (35.0) | 90 (31.8) | ||
 Oocytes retrieved, n | 13.4 ± 6.7 | 12.4 ± 6.0 | 0.017 | 12.9 ± 6.6 | 12.5 ± 5.9 | 0.348 |
 Number of transplantable embryos (n) | 9.9 ± 5.6 | 9.2 ± 4.5 | 0.041 | 9.5 ± 5.5 | 9.2 ± 4.3 | 0.455 |
 Number of top-quality embryos (n) | 4.2 ± 3.5 | 3.4 ± 2.9 | 0.000 | 3.9 ± 3.3 | 3.5 ± 2.9 | 0.118 |
 Endometrial thickness (mm) | 9.8 ± 1.9 | 9.8 ± 2.0 | 0.970 | 9.7 ± 1.9 | 9.7 ± 2.0 | 0.636 |
Endometrial preparation protocol n (%) | ||||||
 Nature | 288 (55.1) | 132 (41.8) | 0.000 | 140 (49.5) | 130 (45.9) | 0.626 |
 HRT | 167 (31.9) | 102 (32.3) | 88 (31.1) | 90 (31.8) | ||
 HRT + GnRHa | 68 (13.0) | 82 (25.9) | 55 (19.4) | 63 (22.3) | ||
Day of blastocyst transfer (%) | ||||||
 Day 5 | 389 (74.4) | 202 (63.9) | 0.001 | 183 (64.7) | 183 (64.7) | 1.000 |
 Day 6 | 134 (25.6) | 114 (36.1) | 100 (35.3) | 100 (35.3) | ||