TABLE 3.
Obstetric and perinatal outcomes of the matched day 3, day 5, day 6, and day 7 vitrified-warmed embryo transfer groups.
| Outcome | Day 3 | Day 5 | Day 6 | Day 7 | P-valuea | P-valueb | P-valuec |
| Gestational age (weeks) | |||||||
| <32 weeks | 2 (0.7) | 0 (0.0) | 3 (1.1) | 1 (1.1) | 0.579 | 0.250 | 1 |
| 32–36 weeks | 9 (3.2) | 19 (6.8) | 15 (5.4) | 6 (6.5) | 0.220 | 0.905 | 0.697 |
| ≥37 weeks | 268 (96.1) | 260 (93.2) | 261 (93.5) | 86 (92.5) | 0.170 | 0.814 | 0.720 |
| Mode of delivery (%) | 0.027 | 0.198 | 0.883 | ||||
| Vaginal | 94 (33.7) | 79 (28.3) | 58 (20.8) | 20 (21.5) | |||
| Cesarean section | 185 (66.3) | 200 (71.7) | 221 (79.2) | 73 (78.5) | |||
| Sex (%) | 0.905 | 0.588 | 0.469 | ||||
| Male | 145 (52.0) | 156 (55.9) | 159 (57.0) | 49 (52.7) | |||
| Female | 134 (48.0) | 123 (44.1) | 120 (43.0) | 44 (47.3) | |||
| Birthweight (g) | 3350 (3020, 3610) | 3400 (3068, 3700) | 3340 (3050, 3690) | 3400 (3095, 3665) | 0.249 | 0.945 | 0.441 |
| Z-score | 0.27 (−0.41, 0.94) | 0.42 (−0.22, 1.21) | 0.32 (−0.34, 1.11) | 0.55 (−0.22, 1.30) | 0.027 | 0.707 | 0.215 |
| <1500 g | 2 (0.7) | 1 (0.4) | 3 (1.1) | 0 (0.0) | 0.562 | 0.750 | 0.576 |
| <2500 g | 7 (2.5) | 9 (3.2) | 11 (3.9) | 2 (2.2) | 0.846 | 0.738 | 0.531 |
| 2500–4500 g | 271 (97.1) | 266 (95.3) | 265 (95.0) | 88 (94.6) | 0.325 | 0.783 | 0.892 |
| >4500 g | 1 (0.4) | 4 (1.4) | 3 (1.1) | 3 (3.2) | 0.050 | 0.373 | 0.168 |
| SGA (<10th percentile) | 16 (5.7) | 13 (4.7) | 10 (3.6) | 2 (2.2) | 0.262 | 0.374 | 0.738 |
| VSGA (<3th percentile) | 5 (1.8) | 4 (1.4) | 3 (1.1) | 1 (1.1) | 0.635 | 0.795 | 0.739 |
| LGA (>90th percentile) | 48 (17.2) | 64 (22.9) | 53 (19.0) | 22 (23.7) | 0.168 | 0.887 | 0.332 |
| VLGA (>97th percentile) | 17 (6.1) | 30 (10.8) | 27 (9.7) | 12 (12.9) | 0.034 | 0.570 | 0.379 |
| Pregnancy complication (%) | |||||||
| GDM | 35 (12.5) | 28 (10.0) | 39 (14.0) | 10 (10.8) | 0.646 | 0.843 | 0.426 |
| PIH | 14 (5.0) | 11 (3.9) | 12 (4.3) | 3 (3.2) | 0.579 | 0.753 | 0.770 |
| PPROM | 8 (2.9) | 5 (1.8) | 4 (1.4) | 4 (4.3) | 0.504 | 0.236 | 0.111 |
| Pre-eclampsia | 7 (2.5) | 6 (2.2) | 3 (1.1) | 1 (1.1) | 0.685 | 0.685 | 0.586 |
| Placenta previa | 2 (0.7) | 5 (1.8) | 6 (2.2) | 3 (3.2) | 0.102 | 0.418 | 0.696 |
| Placental abruption | 2 (0.7) | 2 (0.7) | 1 (0.4) | 1 (1.1) | 0.738 | 0.738 | 0.438 |
| Postpartum hemorrhage | 6 (2.2) | 8 (2.9) | 10 (3.6) | 2 (2.2) | 1 | 0.711 | 0.675 |
PIH, pregnancy-induced hypertension; PPROM, preterm premature rupture of membranes. aP-value for day 3 vs. day 7. bP-value for day 5 vs. day 7. cP-value for day 6 vs. day 7. Bold values indicate statistically significant results.