Table 2.
Ovarian stimulation characteristics and outcomes among the five group.
| Age ≤ 32 | 32 < age ≤ 34 | 34 < age ≤ 36 | 36 < age ≤ 38 | 38 < age ≤ 40 | age > 40 | P | |
|---|---|---|---|---|---|---|---|
| COS protocols (%) | < 0.001 | ||||||
| GnRH agonist protocol | 4122 (84.23%) | 811 (82.59%) | 422 (78.29%) | 248 (71.88%) | 119 (60.41%) | 57 (43.18%) | |
| GnRH antagonist protocol | 772 (15.77%) | 171 (17.41%) | 117 (21.71%) | 97 (28.12%) | 78 (39.59%) | 75 (56.82%) | |
| Gn dosage (IU) | 2181.21 ± 947.55 | 2355.91 ± 901.05 | 2434.18 ± 828.04 | 2540.49 ± 816.40 | 2622.72 ± 742.41 | 2567.50 ± 840.26 | < 0.001 |
| Gn duration (day) | 10.88 ± 2.79 | 10.92 ± 2.64 | 10.70 ± 2.47 | 10.62 ± 2.59 | 10.37 ± 2.30 | 9.82 ± 2.96 | 0.012 |
| Starting dosage of Gn (IU) | 161.28 ± 56.20 | 175.04 ± 60.36 | 192.50 ± 64.73 | 207.45 ± 62.40 | 222.72 ± 59.18 | 245.68 ± 52.94 | < 0.001 |
| No. of retrieved oocytes | 10.95 ± 4.63 | 10.61 ± 4.55 | 10.11 ± 4.66 | 10.09 ± 4.87 | 10.23 ± 4.88 | 8.22 ± 4.70 | < 0.001 |
| No. of frozen embryos | 5.20 ± 3.41 | 4.61 ± 3.01 | 4.22 ± 2.98 | 3.80 ± 2.66 | 3.43 ± 2.53 | 2.72 ± 2.16 | < 0.001 |
| Methods of ART (%) | 0.133 | ||||||
| IVF | 4064 (83.04%) | 841 (85.64%) | 467 (86.64%) | 295 (85.51%) | 170 (86.29%) | 114 (86.36%) | |
| ICSI | 669 (13.67%) | 108 (11.00%) | 64 (11.87%) | 41 (11.88%) | 23 (11.68%) | 16 (12.12%) | |
| Combined | 161 (3.29%) | 33 (3.36%) | 8 (1.48%) | 9 (2.61%) | 4 (2.03%) | 2 (1.52%) | |
| Endometrial thickness (mm) on transfer day | 10.49 ± 2.49 | 10.59 ± 2.60 | 10.56 ± 2.73 | 10.34 ± 2.71 | 10.43 ± 2.98 | 9.62 ± 2.13 | 0.003 |
| Transferred embryo type (%) | 0.004 | ||||||
| Embryos in the cleavage stage | 1358 (27.75%) | 313 (31.87%) | 176 (32.65%) | 113 (32.75%) | 52 (26.40%) | 53 (40.15%) | |
| Blastocyst | 3536 (72.25%) | 669 (68.13%) | 363 (67.35%) | 232 (67.25%) | 145 (73.60%) | 79 (59.85%) | |
| Transferred embryo quality (%) | < 0.001 | ||||||
| Not good | 530 (12.31%) | 138 (15.56%) | 80 (16.99%) | 58 (19.27%) | 42 (27.45%) | 18 (18.56%) | |
| Good | 3774 (87.69%) | 749 (84.44%) | 391 (83.01%) | 243 (80.73%) | 111 (72.55%) | 79 (81.44%) | |
| Cycle type (%) | < 0.001 | ||||||
| Fresh embryo transfer | 2466 (50.39%) | 578 (58.86%) | 318 (59.00%) | 199 (57.68%) | 110 (55.84%) | 50 (37.88%) | |
| FET | 2428 (49.61%) | 404 (41.14%) | 221 (41.00%) | 146 (42.32%) | 87 (44.16%) | 82 (62.12%) | |
| Clinical pregnancy rate (%) | 3166 (64.69%) | 605 (61.61%) | 289 (53.62%) | 181 (52.46%) | 80 (40.61%) | 32 (24.24%) | < 0.001 |
| Ongoing pregnancy rate (%) | 2832 (57.87%) | 531 (54.07%) | 245 (45.45%) | 155 (44.93%) | 63 (31.98%) | 17 (12.88%) | < 0.001 |
| Multiple pregnancy rate (%) | 43(1.36%) | 6(1.16%) | 3(1.10%) | 1(0.57%) | 0 | 0 | 0.332 |