Table 2 Laboratory results and pregnancy outcomes
Item | Spring | Summer | Autumn | Winter | F/ χ2 | P value |
|---|---|---|---|---|---|---|
Cycle number | 659 | 578 | 519 | 534 | ||
Length of Gn used (d) | 13.51 ± 1.95 | 13.72 ± 1.98 | 13.71 ± 1.96 | 13.49 ± 2.06 | 2.261 | 0.079 |
Total dosage of Gn used (IU) | 2380.17 ± 858.13 | 2431.47 ± 821.74 | 2419.98 ± 835.10 | 2444.82 ± 823.40 | 0.683 | 0.563 |
Number of oocytes retrieved (n) | 13.72 ± 5.09 | 13.98 ± 5.74 | 13.85 ± 5.44 | 13.37 ± 4.92 | 1.346 | 0.258 |
Number of 2PN fertilization (n) | 8.56 ± 3.88 | 8.63 ± 4.14 | 8.60 ± 3.99 | 8.49 ± 3.95 | 0.133 | 0.940 |
2PN fertilization rate (%) | 62.54% (5644/9042) | 61.75% (4990/8081) | 62.05% (4461/7189) | 63.48% (4532/7139) | 5.390 | 0.145 |
Number of 2PN cleavage (n) | 8.45 ± 3.86 | 8.52 ± 4.11 | 8.49 ± 3.95 | 8.38 ± 3.91 | 0.129 | 0.943 |
2PN cleavage rate (%) | 98.71% (5571/5644) | 98.70% (4925/4990) | 98.79% (4407/4461) | 98.74% (4475/4532) | 0.198 | 0.978 |
Number of high-quality embryos (n) | 5.19 ± 3.02 | 5.01 ± 3.13 | 5.32 ± 2.97 | 5.31 ± 2.95 | 2.345 | 0.071 |
High-quality embryo rate (%) | 58.70%c,d (3270/5571) | 58.78%c,d (2895/4925) | 62.67%a,b (2762/4407) | 63.42%a,b (2838/4475) | 18.031 | 0.000 |
Number of transferred embryos (n) | 1.83 ± 0.38 | 1.78 ± 0.41 | 1.83 ± 0.38 | 1.80 ± 0.40 | 1.721 | 0.161 |
Day of transfer | 6.986 | 0.072 | ||||
Day 3 (%) | 84.83% (559/659) | 79.41% (459/578) | 83.62% (434/519) | 81.65% (436/534) | ||
Day 5 (%) | 15.17% (100/659) | 20.59% (119/578) | 16.38% (85/519) | 18.35% (98/534) | ||
Biochemical pregnancy rate (%) | 74.66% (492/659) | 76.82% (444/578) | 74.76% (388/519) | 70.22% (375/534) | 6.631 | 0.085 |
Clinical pregnancy rate (%) | 70.71%d (466/659) | 73.18%d (423/578) | 70.13%d (364/519) | 65.17% (348/534) | 8.866 | 0.031 |
Early abortion rate (%) | 10.09% (47/466) | 10.87% (46/423) | 9.07% (33/364) | 8.33% (29/348) | 1.657 | 0.647 |
Live birth rate (%) | 63.13% (416/659) | 64.71% (374/578) | 63.20% (328/519) | 59.18% (316/534) | 3.927 | 0.270 |