| NC (N = 1921) | OS (N = 360) | HRT (N = 1583) | p |
---|---|---|---|---|
No. (%) | No. (%) | No. (%) | ||
Maternal socio-demographic characteristics | ||||
 Age of oocyte retrieval, Mean ± SD, years | 31.25 ± 3.74 | 30.95 ± 3.81 | 30.73 ± 3.69 | < 0.001 |
 Age of embryo transfer, Mean ± SD, years | 31.43 ± 3.74 | 31.04 ± 3.78 | 30.96 ± 3.70 | < 0.001 |
 Pre-gestational BMI, Mean ± SD, kg/m2 | 22.42 ± 3.02 | 22.55 ± 2.99 | 22.35 ± 3.24 | 0.216 |
 Residence | ||||
  Residents | 1271 (66.16) | 228 (63.33) | 1057 (66.77) | 0.731 |
  Immigrants | 650 (33.84) | 132 (36.67) | 526 (33.23) |  |
 Education attainment | ||||
  Primary school or lower | 21 (1.09) | 8 (2.22) | 16 (1.01) | 0.386 |
  Middle school | 223 (11.61) | 43 (11.94) | 207 (13.08) |  |
  High school | 316 (16.45) | 57 (15.83) | 271 (17.12) |  |
  Collage or above | 1361 (70.85) | 252 (70.00) | 1089 (69.79) |  |
 Occupation | ||||
  Employed | 1339 (69.70) | 219 (60.83) | 1127 (71.19) | 0.735 |
  Self-employed | 400 (20.82) | 108 (30.00) | 297 (18.76) |  |
  Unemployed | 182 (9.47) | 33 (9.17) | 159 (10.04) |  |
 Smoking during pregnancy | ||||
  No | 1898 (98.80) | 357 (99.17) | 1571 (99.24) | 0.187 |
  Yes | 23 (1.20) | 3 (0.83) | 12 (0.76) |  |
History of reproduction | ||||
 Parity | ||||
  No | 1754 (91.83) | 333 (92.50) | 1475 (93.18) | 0.132 |
  Yes | 157 (8.17) | 27 (7.50) | 108 (6.82) |  |
 Number of previous abortions | ||||
  0 | 1298 (67.57) | 227 (63.06) | 1093 (69.05) | 0.147 |
  1–2 | 560 (29.15) | 124 (34.44) | 448 (28.30) |  |
  ≥ 3 | 63 (3.28) | 9 (2.50) | 42 (2.65) |  |
 Previous ectopic pregnancy | ||||
  No | 1668 (86.83) | 316 (87.78) | 1378 (87.05) | 0.837 |
  Yes | 253 (13.17) | 44 (12.22) | 205 (12.95) |  |
 Duration of infertility | ||||
  1–2 | 747 (38.89) | 133 (36.94) | 589 (37.21) | 0.195 |
  3–4 | 592 (30.82) | 133 (36.94) | 532 (33.61) |  |
  ≥ 5 | 582 (30.30) | 94 (26.11) | 462 (29.19) |  |
 Primary infertility | ||||
  No | 1104 (57.47) | 207 (57.50) | 924 (58.37) | 0.954 |
  Yes | 817 (42.53) | 153 (42.50) | 659 (41.63) |  |
 Causes of infertility | ||||
  Tubal infertility | 924 (48.10) | 155 (43.06) | 654 (41.31) | < 0.001 |
  Anovulatory | 24 (1.25) | 30 (8.33) | 183 (11.56) |  |
  Endometriosis | 55 (2.86) | 4 (1.11) | 44 (2.78) |  |
  Male-factor infertility | 159 (8.28) | 19 (5.28) | 106 (6.70) |  |
  Unexplained infertility | 321 (16.71) | 70 (19.44) | 196 (12.38) |  |
  Combined a | 438 (22.80) | 82 (22.78) | 400 (25.27) |  |