Table 3.
Characteristics and treatment outcomes of frozen‐thawed embryo transfer cycles in assisted reproductive technology, Japan, 2017
| Variables | FET | Othersa | Total |
|---|---|---|---|
| No. of registered initiated cycles | 197,593 | 1,199 | 198,792 |
| No. of FET | 194,415 | 1,053 | 195,468 |
| No. of cycles with pregnancy | 66,881 | 353 | 67,234 |
| Pregnancy rate per FET | 34.4% | 33.5% | 34.4% |
| SET cycles | 162,343 | 746 | 163,089 |
| Pregnancy following SET cycles | 57,167 | 241 | 57,408 |
| Rate of SET cycles | 83.5% | 70.8% | 83.4% |
| Pregnancy rate following SET cycles | 35.2% | 32.3% | 35.2% |
| Miscarriages | 17,343 | 81 | 17,424 |
| Miscarriage rate per pregnancy | 25.9% | 22.9% | 25.9% |
| Singleton pregnanciesb | 63,391 | 324 | 63,715 |
| Multiple pregnanciesb | 2,168 | 22 | 2,190 |
| Twin pregnanciesb | 2,126 | 22 | 2,148 |
| Triplet pregnanciesb | 42 | 0 | 42 |
| Quadruplet pregnanciesb | 0 | 0 | 0 |
| Multiple pregnancy rateb | 3.3% | 6.4% | 3.3% |
| Live births | 46 396 | 228 | 46 624 |
| Live birth rate per FET | 23.9% | 21.7% | 23.9% |
| Total number of neonates | 47,807 | 235 | 48,042 |
| Singleton live births | 44,820 | 213 | 45,033 |
| Twin live births | 1,471 | 11 | 1,482 |
| Triplet live births | 15 | 0 | 15 |
| Quadruplet live births | 0 | 0 | 0 |
| Pregnancy outcomes | |||
| Ectopic pregnancies | 354 | 2 | 356 |
| Intrauterine pregnancies coexisting with ectopic pregnancy | 3 | 0 | 3 |
| Artificial abortions | 286 | 3 | 289 |
| Stillbirths | 180 | 1 | 181 |
| Fetal reduction | 15 | 0 | 15 |
| Unknown cycles for pregnancy outcomes | 1,901 | 33 | 1,934 |
Abbreviations: FET, frozen‐thawed embryo transfer; SET, single embryo transfer.
a
Including cycles using frozen‐thawed oocytes.
b
Singleton, twin, triplet, and quadruplet pregnancies were defined according to the number of gestational sacs in utero.