Table 1.
Baseline and embryological characteristics of day 5 blastocysts vs. day 6 blastocysts cycles.
| Day 5 (N = 1180) | Day 6 (N = 660) | P value | |
|---|---|---|---|
| Mean donor age (years) | 26.72 ± 0.41 | 26.99 ± 0.12 | 0.08 |
| Mean patient age (years) | 43.71 ± 0.12 | 44.08 ± 0.18 | 0.09 |
| Sperm > 1mil/ml (%) | 1052/1180 (89.15) |
577/660 (87.5) |
0.28 |
| Mean No. of oocytes received per patient | 10.03 ± 0.14 | 9.94 ± 0.08 | 0.38 |
| Fertilization rate (%) | 10,076/11,837 (85.12) | 5479/6552 (83.62) | 0.007 |
| Cleavage rate (%) | 9918/11,837 (83.79) | 5362/6552 (81.83) | 0.0008 |
| Weighted D3 score | 2.10 ± 0.01 | 2.02 ± 0.01 | < 0.0001 |
| Blastocyst development rate (%) |
3730/10,076 (37.02) |
676/5479 (12.34) |
< 0.0001 |
| Freezing rate (%) | 5402/11,837 (45.64) | 2479/6552 (37.84) | < 0.0001 |
| Survival rate (%) |
1265/1333 (94.89) |
693/765 (90.59) |
0.0002 |
| Transfer of 2 blastocysts (%) |
88/1180 (7.46) |
45/659 (6.83) |
0.64 |
Data is presented in mean ± standard error or percentage.