Table I. Description of study variables by data source.
| CARTR Plus | Reabstracted Data | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Variable | N | % | Mean | SD | Median | IQR | N | % | Mean | SD | Median | IQR |
| Intake of patient | ||||||||||||
| Patient age (years) | 876 | 35.5 | 4.63 | 35 | (32–39) | 876 | 35.5 | 4.66 | 35 | (32–39) | ||
| Oocyte provider age (years) | 860 | 34.2 | 4.58 | 31 | (34–38) | 874 | 34.7 | 7.06 | 34 | (31–38) | ||
| Reason for treatment cycle | ||||||||||||
| Diminished ovarian reserve | ||||||||||||
| Yes | 149 | 17.0 | 150 | 17.1 | ||||||||
| No | 727 | 83.0 | 726 | 82.9 | ||||||||
| Advanced female age | ||||||||||||
| Yes | 187 | 21.4 | 125 | 14.3 | ||||||||
| No | 689 | 78.7 | 751 | 85.7 | ||||||||
| FSH (IU/L) | 509 | 7.20 | 3.59 | 6.70 | (5.20–8.00) | 734 | 6.81 | 2.95 | 6.30 | (5.00–7.90) | ||
| AFC (# follicles) | 362 | 16.2 | 11.8 | 13.5 | (8.00–21.0) | 583 | 16.3 | 11.2 | 14.0 | (9.00–21.0) | ||
| AMH (ng/dL)* | 77 | 2.20 | 2.14 | 1.30 | (0.90–2.80) | 202 | 2.46 | 2.56 | 1.60 | (0.80–3.30) | ||
| Stimulation | ||||||||||||
| Cycle type | ||||||||||||
| IVF | 607 | 69.3 | 602 | 68.7 | ||||||||
| FET | 245 | 28.0 | 245 | 28.0 | ||||||||
| Frozen oocyte IVF | 14 | 1.60 | 18 | 2.05 | ||||||||
| Oocyte banking | 10 | 1.14 | 11 | 1.26 | ||||||||
| Cancelled cycle | ||||||||||||
| Yes | 60 | 6.85 | 62 | 7.08 | ||||||||
| No | 816 | 93.2 | 814 | 92.9 | ||||||||
| Reason for cancelled | ||||||||||||
| Low ovarian response | 47 | 78.3 | 38 | 61.3 | ||||||||
| Premature ovulation | 3 | 5.00 | 3 | 4.84 | ||||||||
| Other | 10 | 16.7 | 10 | 16.1 | ||||||||
| Missing | 0 | 0.00 | 11 | 17.7 | ||||||||
| Retrieval | ||||||||||||
| Oocyte origin | ||||||||||||
| Fresh own oocytes | 672 | 82.4 | 750 | 92.1 | ||||||||
| Fresh donor oocytes | 35 | 4.29 | 39 | 4.79 | ||||||||
| Other | 3 | 0.37 | 23 | 2.83 | ||||||||
| Missing | 106 | 13.0 | 2 | 0.25 | ||||||||
| Embryo transfer | ||||||||||||
| Embryo transfer | ||||||||||||
| Yes | 655 | 80.3 | 654 | 80.3 | ||||||||
| No | 152 | 18.6 | 160 | 19.7 | ||||||||
| Missing | 9 | 1.10 | 0 | 0.00 | ||||||||
| ET day | 655 | 2.57 | 2.12 | 647 | 4.39 | 1.16 | ||||||
| Fresh cycles | 418 | 4.02 | 1.09 | 5.00 | (3.00–5.00) | 418 | 4.00 | 1.10 | 5.00 | (3.00–5.00) | ||
| 2 | 26 | 6.22 | 27 | 6.46 | ||||||||
| 3 | 166 | 39.7 | 168 | 40.2 | ||||||||
| 5 | 225 | 53.8 | 222 | 53.1 | ||||||||
| 6 | 1 | 0.24 | 1 | 0.24 | ||||||||
| Frozen cycles | 237 | 0.00 | 0.00 | 229 | 5.10 | 0.93 | 5.00 | (5.00–6.00) | ||||
| 2 | 0 | 1 | 0.42 | |||||||||
| 3 | 0 | 21 | 8.90 | |||||||||
| 4 | 0 | 13 | 5.51 | |||||||||
| 5 | 0 | 120 | 50.9 | |||||||||
| 6 | 0 | 69 | 29.2 | |||||||||
| >6 | 0 | 5 | 2.11 | |||||||||
| Missing | 7 | 2.97 | ||||||||||
| # embryos transferred | ||||||||||||
| 1 | 362 | 55.3 | 362 | 55.4 | ||||||||
| 2 | 273 | 41.7 | 273 | 41.7 | ||||||||
| 3 | 17 | 2.60 | 16 | 2.45 | ||||||||
| 4 | 3 | 0.46 | 3 | 0.46 | ||||||||
| eSET or eDET | ||||||||||||
| Yes | 387 | 59.1 | 475 | 72.6 | ||||||||
| No | 268 | 40.9 | 177 | 27.1 | ||||||||
| Missing | 0 | 0.00 | 2 | 0.31 | ||||||||
| Embryology | ||||||||||||
| Embryo cryopreservation | ||||||||||||
| IVF | ||||||||||||
| Vitrification | 267 | 94.0 | 267 | 94.0 | ||||||||
| Slow-freeze | 17 | 5.99 | 16 | 5.63 | ||||||||
| Mixed | 0 | 0.00 | 1 | 0.35 | ||||||||
| FET | ||||||||||||
| Vitrification | 142 | 58.0 | 194 | 79.2 | ||||||||
| Slow-freeze | 20 | 8.16 | 49 | 20.0 | ||||||||
| Mixed | 0 | 0.00 | 1 | 0.41 | ||||||||
| Missing | 83 | 33.9 | 1 | 0.41 | ||||||||
| # embryos thawed | 245 | 1.95 | 1.76 | 1.00 | (1.00–2.00) | 244 | 1.95 | 1.77 | 1.00 | (1.00–2.00) | ||
| # embryos utilizable after thaw | 245 | 1.47 | 0.99 | 1.00 | (1.00–2.00) | 244 | 1.46 | 0.92 | 1.00 | (1.00–2.00) | ||
| Pregnancy | ||||||||||||
| Pregnancy type | ||||||||||||
| Not pregnant | 522 | 59.6 | 519 | 59.3 | ||||||||
| Biochemical | 45 | 5.14 | 52 | 5.94 | ||||||||
| Clinical intrauterine | 285 | 32.5 | 289 | 33.0 | ||||||||
| Other | 2 | 0.23 | 2 | 0.23 | ||||||||
| Unknown | 22 | 2.51 | 14 | 1.60 | ||||||||
| # fetal sac | ||||||||||||
| 1 | 221 | 77.5 | 222 | 76.8 | ||||||||
| 2 | 63 | 22.1 | 62 | 21.5 | ||||||||
| 3 | 1 | 0.35 | 2 | 0.69 | ||||||||
| Missing | 0 | 0.00 | 3 † | 1.04 | ||||||||
| # fetal heart | ||||||||||||
| 0 | 26 | 9.12 | 28 | 9.69 | ||||||||
| 1 | 202 | 70.9 | 206 | 71.3 | ||||||||
| 2 | 56 | 19.7 | 52 | 18.0 | ||||||||
| 3 | 1 | 0.35 | 1 | 0.35 | ||||||||
| Missing | 0 | 0.00 | 2 | 0.69 | ||||||||
| Chorionicity | ||||||||||||
| 1 | 4 | 5.97 | 5 | 6.15 | ||||||||
| 2 | 59 | 88.1 | 45 | 69.2 | ||||||||
| 3 | 1 | 1.49 | 1 | 1.54 | ||||||||
| Missing | 3 | 4.48 | 15 | 23.1 | ||||||||
AFC: antral follicle count, AMH: anti-Müllerian hormone, CARTR Plus: Canadian Assisted Reproductive Technologies Register Plus, eDET: elective double embryo transfer, eSET: elective single embryo transfer, ET: embryo transfer, FET: frozen embryo transfer, IQR: interquartile range, N: Number or patients
*AMH levels were converted from pmol/L to ng/dL using a conversion factor of 7.14 (Almog et al., 2011)
†There was an error in data entry which was recoded as missing