Table 1.
Patient characteristics, cycle parameters and serum hCG-β levels (mean ± SD), and the fold change of hCG-β levels between postovulatory day (POD) 12 and 14 of pregnancies achieved after fresh IVF-ET and frozen-thawed ET cycles
| Fresh cycles (784 cycles in 738 patients) |
Frozen-thawed cycles (353 cycles in 327 patients) |
|||||||
|---|---|---|---|---|---|---|---|---|
| Biochemical pregnancy | Early pregnancy loss | Live Birth | P valuea | Biochemical pregnancy | Early pregnancy loss | Live Birth | P valuea | |
| No. of cycles | 196 | 136 | 452 | 83 | 69 | 201 | ||
| Age (years) | 35.4 ± 3.9 | 36.7 ± 4.3 | 34.4 ± 3.5 | <0.001 | 34.8 ± 3.9 | 35.3 ± 3.6 | 33.3 ± 3.5 | <0.001 |
| Age of husband (years) | 37.3 ± 4.4 | 38.2 ± 4.4 | 36.9 ± 4.3 | 0.014 | 37.8 ± 4.3 | 37.1 ± 4.3 | 35.9 ± 4.5 | 0.004 |
| BMI (kg/m2) | 20.8 ± 3.3 | 21.3 ± 2.6 | 21.0 ± 2.8 | 0.371 | 21.5 ± 3.9 | 21.2 ± 3.7 | 20.8 ± 2.6 | 0.195 |
| No. of IVF | 2.2 ± 1.6 | 2.2 ± 1.9 | 2.2 ± 1.7 | 0.849 | 3.8 ± 2.2 | 3.3 ± 1.8 | 3.0 ± 1.4 | 0.002 |
| No. of embryos transferred | 2.8 ± 0.9 | 2.9 ± 1.0 | 2.8 ± 0.9 | 0.654 | 3.2 ± 0.9 | 3.2 ± 0.9 | 3.0 ± 0.8 | 0.097 |
| Basal FSH on cycle day 2 | 9.8 ± 5.5 | 9.4 ± 5.2 | 9.4 ± 4.0 | 0.671 | – | – | – | – |
| E2 level on hCG injection day | 1744.5 ± 1683.2 | 1653.9 ± 1282.4 | 1827.6 ± 1658.6 | 0.524 | – | – | – | – |
| Indication of IVF | P valueb | P valueb | ||||||
| Male factor (%) | 51 (26.0) | 22 (16.2) | 111 (24.6) | 0.139 | 20 (24.1) | 18 (26.1) | 60 (29.9) | 0.580 |
| Tubal factor (%) | 31 (15.8) | 18 (13.2) | 73 (16.2) | 0.709 | 27 (32.5) | 16 (23.2) | 45 (22.4) | 0.186 |
| Ovulatory factor (%) | 13 (6.6) | 17 (12.5) | 40 (8.8) | 0.182 | 5 (6.0) | 5 (7.2) | 11 (5.5) | 0.865 |
| Endometriosis (%) | 34 (17.3) | 19 (14.0) | 65 (14.4) | 0.399 | 2 (2.4) | 4 (5.8) | 20 (10.0) | 0.074 |
| Advanced age (%) | 8 (4.1) | 14 (10.3) | 16 (3.5) | 0.005 | 1 (1.2) | 2 (2.9) | 4 (2.0) | 0.757 |
| Uterine (%) | 4 (2.0) | 3 (2.2) | 6 (1.3) | 0.694 | 5 (6.0) | 2 (2.9) | 4 (2.0) | 0.204 |
| Unexplained (%) | 55 (28.1) | 43 (31.6) | 141 (31.2) | 0.693 | 23 (27.7) | 22 (31.9) | 58 (28.9) | 0.843 |
| Serum β-hCG level | P valuea | P valuea | ||||||
| POD 12 hCG-β (mIU/mL) | 20.0 ± 17.2c,d | 47.9 ± 30.3e | 65.2 ± 32.4 | <.001 | 29.3 ± 29.1c,d | 51.5 ± 39.4e | 73.0 ± 42.1 | <.001 |
| POD 14 hCG-β (mIU/mL) | 38.6 ± 42.1c,d | 137.5 ± 87.1e | 197.2 ± 98.1 | <.001 | 60.2 ± 71.0c,d | 148.9 ± 122.1e | 222.6 ± 131.6 | <.001 |
| Increase of hCG-β between POD 12 and 14 (fold) | 2.0 ± 1.3c,d | 3.0 ± 1.0e | 3.1 ± 0.8 | <.001 | 1.9 ± 0.9c,d | 3.0 ± 1.0e | 3.1 ± 0.9 | <.001 |
a P values were calculated among study groups, including biochemical pregnancy loss and live birth groups, using ANOVA or Kruskal-Wallis test
b P values were calculated among three groups using chi-square test
cBiochemical pregnancy vs early pregnancy loss, P < 0.05
dBiochemical pregnancy vs live birth, P < 0.05
eEarly pregnancy loss vs live birth, P < 0.05