Table 2.
Baseline characteristics of cycles resulting in live births.
| Characteristic | Biopsy group | Control group | p-value |
|---|---|---|---|
| FET cycles, n | 1873 | 3034 | |
| Age (years) | 33 (29-37) | 31 (29-34) | <0.001 |
| BMI (kg/m2) | 21.64 (20.03-23.33) | 21.78 (20.03-23.44) | 0.447 |
| Duration of infertility (years) | 2 (1-4) | 3 (2-5) | <0.001 |
| Basal values | |||
| FSH (mIU/mL) | 5.67 (4.73-6.75) | 5.42 (4.47-6.44) | <0.001 |
| LH (mIU/mL) | 3.50 (2.52-4.69) | 3.37 (2.33-4.79) | 0.028 |
| E2 (pg/mL) | 34.00 (26.00-44.61) | 32.00 (24.00-44.00) | <0.001 |
| Endometrial thickness on the day before transfer (mm) | 11.90 (10.60-13.20) | 11.90 (10.70-13.10) | 0.824 |
| Advanced age, % (n) | 39.19 (734) | 21.16 (642) | <0.001 |
| Chromosomal abnormality, % (n) | 30.86 (578) | 0.99 (30) | <0.001 |
| Monogenic disease, % (n) | 15.59 (292) | 3.89 (118) | <0.001 |
| RSA, % (n) | 27.66 (518) | 2.60 (79) | <0.001 |
| RIF, % (n) | 4.06 (76) | 2.27 (69) | <0.001 |
| Rate of high-quality embryos transferred, % (n) | 83.72 (1568) | 67.24 (2040) | <0.001 |
| Endometrial preparation protocols, % (n) |
<0.001 | ||
| NC-FET | 87.77 (1644) | 78.21 (2373) | |
| HT-FET | 6.73 (126) | 11.96 (363) | |
| Down-regulating HT-FET | 5.50 (103) | 9.82 (298) | |
| HCG12 (mIU/mL) | 616 (427-847) | 634 (441-851) | 0.136 |
Variables are expressed as medians (interquartile range) unless otherwise stated. FET, frozen embryo transfer; BMI, body mass index; FSH, follicle-stimulating hormone; LH, luteinizing hormone; E2, estradiol; RSA, recurrent spontaneous abortion; RIF, recurrent implantation failure NC, natural cycle; HT, hormone therapy; HCG12, serum β human chorionic gonadotropin on 12 days after blastocyst transfer.