TABLE 1.
Pregnancy outcomes of day 3, day 5, day 6, and day 7 vitrified-warmed embryo transfer groups.
| Day 3 (n = 8591) | Day 5 (n = 1961) | Day 6 (n = 4910) | Day 7 (n = 413) | P-valuea | P-valueb | P-valuec | |
| Clinical pregnanciesd | 4313/8591 (50.2) | 1194/1961 (60.9) | 2685/4910 (54.7) | 136/413 (32.9) | <0.001 | <0.001 | <0.001 |
| Miscarriages | 569/4313 (13.2) | 174/1194 (14.6) | 467/2685 (17.4) | 26/136 (19.1) | 0.046 | 0.160 | 0.605 |
| 1st trimester | 496/4313 (11.5) | 152/1194 (12.7) | 414/2685 (15.4) | 24/136 (17.6) | 0.028 | 0.109 | 0.484 |
| 2st trimester | 73/4313 (1.7) | 22/1194 (1.8) | 53/2685 (2.0) | 2/136 (1.5) | 0.843 | 0.758 | 0.679 |
| Ectopic | 125/4313 (2.9) | 24/1194 (2.0) | 21/2685 (0.8) | 0/136 (0) | 0.033 | 0.163 | 0.622 |
| Live birthsd | 3608/8591 (42.0) | 994/1961 (50.7) | 2193/4910 (44.7) | 110/413 (26.6) | <0.001 | <0.001 | <0.001 |
| Stillbirths | 11/3608 (0.3) | 2/994 (0.2) | 4/2193 (0.2) | 0/413 (0) | 0.617 | 0.362 | 0.385 |
Clinical pregnancy was diagnosed by the ultrasonographic visualization of one or more gestational sac after embryo transfer; Miscarriage rate was defined as a loss of clinical pregnancy before the 20th gestational week; Data are were presented as numbers and proportion (%). aP-value for day 3 vs. day 7. bP-value for day 5 vs. day 7. cP-value for day 6 vs. day 7. dInclusion of single and twin pregnancies.