TABLE 3.
Characteristics and treatment outcomes of frozen cycles in assisted reproductive technology in Japan, 2022.
| Variables | FET | Other a | Total |
|---|---|---|---|
| No. of registered cycles | 262 146 | 1869 | 264 015 |
| No. of FET | 258 217 | 1688 | 259 905 |
| No. of cycles of pregnancy | 97 664 | 643 | 98 307 |
| Pregnancy rate per FET | 37.8% | 38.1% | 37.8% |
| SET cycles | 220 292 | 1386 | 221 678 |
| Pregnancy following SET cycles | 85 432 | 538 | 85 970 |
| Rate of SET cycles | 85.3% | 82.1% | 85.3% |
| Pregnancy rate following SET cycles | 38.8% | 38.8% | 38.8% |
| Miscarriages | 24 969 | 181 | 25 150 |
| Miscarriage rate per pregnancy | 25.6% | 28.2% | 25.6% |
| Singleton pregnancies b | 93 406 | 617 | 94 023 |
| Multiple pregnancies b | 3000 | 16 | 3016 |
| Twin pregnancies | 2939 | 16 | 2955 |
| Triplet pregnancies | 54 | 0 | 54 |
| Quadruplet pregnancies | 6 | 0 | 6 |
| Quintuplet pregnancies | 1 | 0 | 1 |
| Multiple pregnancy rate | 3.1% | 2.5% | 3.1% |
| Live births | 69 834 | 435 | 70 269 |
| Live birth rate per FET | 27.0% | 25.8% | 27.0% |
| Total no. of neonates | 71 733 | 446 | 72 179 |
| Singleton live births | 67 646 | 424 | 68 070 |
| Twin live births | 2018 | 11 | 2029 |
| Triplet live births | 17 | 0 | 17 |
| Quadruplet live births | 0 | 0 | 0 |
| Ectopic pregnancies | 476 | 1 | 477 |
| Heterotopic pregnancies | 23 | 0 | 23 |
| Artificial abortions | 436 | 4 | 440 |
| Stillbirths | 239 | 5 | 244 |
| Fetal reductions | 18 | 0 | 18 |
| Cycles with unknown pregnancy outcomes | 1430 | 8 | 1438 |
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 on the basis of the number of gestational sacs in utero.