Variables | Total | Nanjing | Changzhou | P |
---|---|---|---|---|
Total number | 5485 | 4165 | 1320 | Â |
Maternal age | 30.01 ± 4.03 | 29.89 ± 4.03 | 30.42 ± 4.03 | <0.001 * |
Maternal BMI | 22.08 ± 3.03 | 22.04 ± 2.99 | 22.21 ± 3.16 | 0.227 |
Paternal BMI | 24.23 ± 3.09 | 24.18 ± 2.98 | 24.37 ± 3.39 | 0.131 |
Infertility type | 0.593 | |||
 Primary | 2781(53.0%) | 2165(52.8%) | 616(53.7%) |  |
 Secondary | 2466(47.0%) | 1935(47.2%) | 531(46.3%) |  |
COH protocol | <0.001 * | |||
 GnRH-a long protocol | 3406(63.1%) | 2311(56.7%) | 1095(83.0%) |  |
 GnRH-a short protocol | 1573(29.2%) | 1448(35.5%) | 125(9.5%) |  |
 GnRH antagonist protocol | 95(1.8%) | 95(2.3%) | 0(0.0%) |  |
 Minimal stimulation protocol | 186(3.4%) | 111(2.7%) | 75(5.7%) |  |
 GnRH-a rolonged protocol | 123(2.3%) | 108(2.6%) | 15(1.1%) |  |
 Other protocol | 13(0.2%) | 4(0.1%) | 9(0.7%) |  |
Total Gn dose | 1808.01 ± 662.11 | 1833.67 ± 613.50 | 1728.88 ± 788.45 | <0.001 * |
Groups of total Gn dose | <0.001 * | |||
  < 1808.01 | 3181(59.0%) | 2344(57.6%) | 837(63.4%) |  |
  ≥ 1808.01 | 2208(41.0%) | 1725(42.4%) | 483(36.6%) |  |
Fertilization methods | <0.001 * | |||
 IVF | 4543(83.9%) | 3641(88.8%) | 902(68.3%) |  |
 ICSI | 875(16.1%) | 457(11.2%) | 418(31.7%) |  |
Cycle type | <0.001 * | |||
 Fresh | 2675(51.9%) | 2202(57.5%) | 473(35.8%) |  |
 Frozen | 2477(48.1%) | 1630(42.5%) | 847(64.2%) |  |
No. of embryos transferred | <0.001 * | |||
 1 | 474(8.7%) | 442(10.7%) | 32(2.4%) |  |
 2 | 4324(79.6%) | 3088(75.0%) | 1236(93.6%) |  |
 3 | 655(11.5%) | 585(14.2%) | 52(3.9%) |  |
Cleavage-stage embryo or blastocyst | ||||
 Cleavage-stage embryo | 3860(73.3%) | 2540(64.4%) | 1320(100.0%) |  |
 Blastocyst | 1405(26.7%) | 1405(35.6%) | 0(0.0%) |  |
Serum hCG levels 14 days after transfer | 695.30 ± 515.44 | 619.49 ± 470.08 | 861.75 ± 568.97 | <0.001 * |
Groups of serum hCG levels 14Â days after transfer | <0.001 * | |||
  < 695.30 | 2205(52.2%) | 1598(55.5%) | 607(46.3%) |  |
  ≥ 695.30 | 1988(47.8%) | 1283(44.5%) | 705(53.7%) |  |