|  < 35 years of age |  ≥ 35 years of age | ||||
---|---|---|---|---|---|---|
Group A | Group B | P | Group A | Group B | P | |
Cycles (n) | 558 | 665 | Â | 165 | 235 | Â |
female age(year) | 29.84 ± 2.75 | 29.93 ± 2.86 | 0.274 | 36.65 ± 1.41 | 36.65 ± 1.37 | 0.498 |
BMI (kg/m2) | 21.83 ± 3.31 | 21.47 ± 3.13 | 0.154 | 22.43 ± 3.69 | 22.20 ± 3.73 | 0.742 |
Infertility duration (years) | 4.01 ± 2.44 | 3.98 ± 2.37 | 0.454 | 5.52 ± 3.75 | 5.28 ± 3.72 | 0.284 |
Type of infertility | Â | Â | 0.652 | Â | Â | 0.754 |
 Primary infertility | 58.42 (326/558) | 57.14 (380/665) |  | 32.12 (53/165) | 33.62 (79/235) |  |
 Secondary infertility | 41.58 (232/558) | 42.86 (285/665) |  | 67.88 (112/165) | 66.38 (156/235) |  |
Fertilization method | Â | Â | 0.160 | Â | Â | 0.259 |
 IVF | 79.57 (444/558) | 75.04 (499/665) |  | 84.85 (140/165) | 85.53 (201/235) |  |
 ICSI | 16.85 (94/558) | 20.15 (134/665) |  | 12.12 (20/165) | 13.19 (31/235) |  |
 IVF + ICSI | 3.58 (20/558) | 4.81 (32/665) |  | 3.03 (5/165) | 1.28 (2/235) |  |
Endometrial preparation (%) | Â | Â | 0.061 | Â | Â | 0.276 |
 Natural | 31.72 (177/558) | 36.84 (245/665) |  | 48.48 (80/165) | 42.98 (101/235) |  |
 HRT | 68.28 (381/558) | 63.16 (420/665) |  | 51.52 (85/165) | 57.02 (134/235) |  |
Endometrial thickness (mm) | 8.96 ± 1.42 | 9.07 ± 1.46 | 0.085 | 8.89 ± 1.44 | 9.05 ± 1.46 | 0.956 |