Table 2.
Patient characteristics stratified by treatment protocol among patients receiving embryo transfer cycles.
| Characteristics | Study group (28 patients, 78 FET cycles) | Control group (54 patients, 102 FET cycles) | Difference study vs. control | Protocol A (48 patients, 102 FET cycles) | Protocol B (30 patients, 78 FET cycles) | Difference protocol A vs. B | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| N | Mean (sd) or % | N | Mean (sd) or % | p-value | N | Mean (sd) or % | N | Mean (sd) or % | p-value | |
| Maternal age at FET (years) | 78 | 42.71 (3.36) | 102 | 40.66 (3.11) | <0.0001*** | 102 | 41.12 (3.32) | 78 | 42.1 (3.38) | 0.0523 |
| BMI (kg/m2) | 78 | 22.17 (2.51) | 102 | 22.88 (3.43) | 0.1062 | 102 | 23.52 (3.46) | 78 | 21.34 (1.89) | <0.0001*** |
| Infertility year (year) | 78 | 5.22 (2.94) | 102 | 5.14 (2.95) | 0.8579 | 102 | 5.17 (2.88) | 78 | 5.17 (3.02) | 0.9996 |
| AMH (ng/mL) | 78 | 0.35 (0.29) | 102 | 0.54 (0.31) | <0.0001*** | 102 | 0.48 (0.33) | 78 | 0.44 (0.29) | 0.4460 |
| No. 1 transferred embryo grade | 78 | 1.33 (0.47) | 102 | 1.33 (0.47) | 1.0000 | 102 | 1.31 (0.47) | 78 | 1.36 (0.48) | 0.5280 |
| No. 2 transferred embryo grade | 78 | 1.91 (0.46) | 102 | 1.96 (0.53) | 0.4938 | 102 | 1.97 (0.5) | 78 | 1.9 (0.50) | 0.3302 |
| Sum of transferred embryo grades | 78 | 3.22 (0.73) | 102 | 3.29 (0.78) | 0.5019 | 102 | 3.27 (0.75) | 78 | 3.24 (0.78) | 0.7881 |
| ET failure history | ||||||||||
| None | 20 | 25.64% | 30 | 29.41% | 0.5757 | 30 | 29.41% | 20 | 25.64% | 0.5757 |
| At least one | 58 | 74.36% | 72 | 70.59% | 72 | 70.59% | 58 | 74.36% | ||
| Pregnancy outcomes | ||||||||||
| Ongoing pregnancy rate (%) | 19 | 24.36% (19/78) | 22 | 21.57% (22/102) | 0.6583 | 21 | 20.59% (21/102) | 20 | 25.64% (20/78) | 0.4231 |
| Live birth rate (%) | 15 | 19.23% (15/78) | 14 | 13.73% (14/102) | 0.3195 | 14 | 13.73% (14/102) | 15 | 19.23% (15/78) | 0.3195 |
sd, standard deviation; FET, frozen embryo transfer; BMI, body mass index; AMH, anti-Müllerian hormone; S, study group receiving cotreatment of clomiphene citrate and letrozole in mild ovarian stimulation; C, control group receiving conventional ovarian stimulation; A, protocol A, where patients received ovarian stimulation with gonadotropin-releasing hormone (GnRH) antagonist protocol; B, protocol B, where patients received ovarian stimulation with progestin-primed ovarian stimulation (PPOS) protocol.
•Definition of embryo grade definition: 1 = an embryo with excellent quality and no fragmentation; 2 = an embryo with good quality and 1%-20% fragmentation; and 3 = an embryo with fair quality and 21%-50% fragmentation.
•Difference in patient characteristics was tested using t-tests (for continuous variables) and chi-square tests (for dichotomous and categorical variables).
•*** indicates p-value <0.001.