Table 1.
Comparison of basic characteristics between the two groups
| Group1 | Group2 | P | |
|---|---|---|---|
| n | 421 | 999 | |
| Age (y) | 32.45 ± 4.45 | 32.43 ± 4.29 | 0.343 |
| Type of infertility | |||
| Primary infertility (%) | 43.9% (185/421) | 40.0% (400/999) | 0.172 |
| Secondary infertility (%) | 56.1% (236/421) | 60.0% (599/999) | 0.172 |
| Years of infertility(y) | 3.63 ± 2.61 | 3.47 ± 2.42 | 0.120 |
| Infertility factors | |||
| Fallopian tube factor (%) | 98.6% (415/421) | 98.8% (987/999) | 0.730 |
| Male factor (%) | 9.0% (38/421) | 9.9% (99/999) | 0.606 |
| Immunological factors (%) | 0.2% (1/421) | 0.1% (1/999) | 0.528 |
| Unspecified reasons (%) | 0.5% (2/421) | 0.1% (1/999) | 0.160 |
| Repeated implant failure (%) | 6.7% (28/421) | 7.3% (73/999) | 0.660 |
| Recurrent spontaneous abortion (%) | 0.00 | 0.6% (6/999) | 0.188 |
| BMI (kg/m2) | 24.15 ± 3.80 | 24.00 ± 3.66 | 0.183 |
| AMH(ng/ml) | 5.33 ± 3.20 | 5.36 ± 3.15 | 0.064 |
| FSH (mIU/ml) | 6.91 ± 2.94 | 7.09 ± 2.79 | 0.844 |
| LH (mIU/ml) | 6.37 ± 4.09 | 6.59 ± 4.58 | 0.690 |
| E2 (pg/ml) | 36.92 ± 14.55 | 37.95 ± 12.67 | 0.182 |
| P (ng/ml) | 0.38 ± 0.18 | 0.35 ± 0.18 | 0.656 |
| T (ng/ml) | 0.49 ± 0.35 | 0.48 ± 0.30 | 0.577 |
| Basal endometrial thickness (mm) | 5.37 ± 1.33 | 5.33 ± 1.21 | 0.130 |
| Number of embryos transferred | 1.66 ± 0.47 | 1.68 ± 0.47 | 0.139 |
| Number of quality embryos transferred | 0.58 ± 0.61 | 0.54 ± 0.60 | 0.806 |
| Previous embryo transfer times | 0.68 ± 1.07 | 0.79 ± 1.20 | 0.285 |