Table 2. Live Birth, Clinical Pregnancy, and Miscarriage Rates in Fresh vs Cryopreserved-Thawed Embryo Transfer Cycles Derived From Freshly Inseminated Donor Oocytes.
| Outcomes | No. (%) | Absolute difference, % (95% CI) | Relative risk (95% CI) | ||
|---|---|---|---|---|---|
| Fresh embryo transfer (n = 15 308) | Cryopreserved-thawed embryo transfer (n = 36 634) | Unadjusted | Adjusteda | ||
| Primary outcome | |||||
| Live birth | 8665 (56.6) | 16 126 (44.0) | 12.6 (11.7 to 13.5) | 1.29 (1.26-1.31) | 1.42 (1.39-1.46) |
| Secondary outcomes | |||||
| Clinical pregnancy | 10 209 (66.7) | 19 845 (54.2) | 12.5 (11.6 to 13.4) | 1.23 (1.21-1.25) | 1.34 (1.31-1.37) |
| Miscarriage | 1416 (9.3) | 3453 (9.4) | 0.2 (−0.4 to 0.7) | 0.98 (0.93-1.04) | 0.98 (0.91-1.07) |
a
Adjusted for donor age, day of embryo transfer, use of a gestational carrier, and assisted hatching.