Table 1.
Clinical outcomes of frozen-thawed blastocyst transfers in LZD and PZD groups
| Variable | LZD group | PZD group | P value |
|---|---|---|---|
| No. of frozen-thawed cycles | 60 | 60 | NA |
| No. of frozen-thawed blastocysts (≧ grade 3BB) | 122 | 132 | NA |
| Complete hatching rates of blastocysts before cryopreservation (%)a | 4.9 % (6/122) | 6.1 % (8/132) | 0.690 |
| Complete hatching rates of blastocysts at 5 h after thawing (%)a | 52.4 % (64/122) | 31.8 % (42/132) | 0.001 |
| Average No. of transferred blastocysts | 2.0 ± 0.7 | 2.2 ± 0.8 | NS |
| Implantation rates (%) | 40.9 % (50/122) | 25.7 % (34/132) | 0.010 |
| Clinical pregnancy rates (%) | 63.0 % (38/60) | 40.0 % (24/60) | 0.011 |
| Ongoing pregnancy rates (%) | 50.0 % (30/60) | 33.3 % (20/60) | 0.064 |
NS not statistically significant, NA not assessable
aComplete hatching blastocysts mean the hatched blastocysts or the hatching blastocysts escaped ICM from ZP