Table 3.
Results for embryo transfer procedures, number of unused embryos, number of frozen embryos, utilisation rate in the intention-to-treat population. Values are mean (standard deviation) unless stated otherwise
| Blastocyst stage group (n=603) | Cleavage stage group (n=599) | Mean difference (95% CI) | P value | |
|---|---|---|---|---|
| Embryo transfer procedures: | ||||
| Overall | 1.99 (1.38) | 2.37 (1.64) | −0.39 (−0.56 to −0.21) | <0.001 |
| Women with live birth | 1.55 (0.99) | 1.82 (1.24) | −0.27 (−0.43 to −0.10) | <0.001 |
| Women with no live birth | 2.60 (1.60) | 3.15 (1.81) | 0.54 (−0.84 to −0.24) | <0.001 |
| No of embryos transferred: | ||||
| Overall | 2.09 (1.40) | 2.54 (1.78) | −0.45 (−0.63 to −0.27) | <0.001 |
| Women with live birth | 1.62 (1.00) | 1.90 (1.30) | −0.28 (−0.45 to −0.11) | 0.002 |
| Women with no live birth | 2.76 (1.61) | 3.45 (1.96) | −0.68 (−1.00 to −0.36) | <0.001 |
| Unused embryos after 12 months: | ||||
| Overall | 2.06 (2.43) | 2.71 (3.12) | −0.65 (−0.97 to −0.33) | <0.001 |
| Women with live birth | 3.12 (2.35) | 4.10 (3.14) | −0.98 (−1.39 to −0.57) | <0.001 |
| Women with no live birth | 0.54 (1.62) | 0.76 (1.75) | −0.21 (−0.51 to 0.09) | 0.165 |
| Total No (%) of women | 354 (58.7) | 384 (64.2) | −0.05 (−0.11 to 0.001) | 0.05 |
| Women with live birth | 312 (51.7) | 325 (54.3) | −0.05 (−0.09 to −0.006) | 0.03 |
| Women with no live birth | 42 (7.0) | 59 (9.9) | −0.07 (−0.14 to 0.003) | 0.06 |
| Mean (SD) total No of frozen embryos | 3.21 (2.55) | 4.39 (3.30) | −1.18 (−1.51 to −0.85) | <0.001 |
| Embryo utilisation rate*: | ||||
| Overall | 2535/4590 (55.3) | 3226/4543 (71.0) | −0.14 (−0.17 to −0.12) | <0.001 |
| Women with live birth | 1689/2881 (58.6) | 2109/2793 (75.5) | −0.14 (−0.17 to −0.11) | <0.001 |
| Women with no live birth | 846/1709 (49.5) | 1117/1750 (63.9) | −0.14 (−0.17 to −0.12) | <0.001 |
CI=confidence interval.
*
Calculated by dividing number of fresh transferred embryos+number of cryopreserved embryos by number of embryos available on day 2 after oocyte retrieval.