Table 3.

Characteristics and treatment outcomes of frozen cycles in assisted reproductive technology, Japan, 2016

Variables	FET	Others[Link]	Total
No. of registered cycles	190 541	1222	191 763
No. of FET	187 132	1100	188 232
No. of cycles with pregnancy	62 432	294	62 726
Pregnancy rate per FET (%)	33.4	26.7	33.3
SET cycles	154 801	849	155 650
Pregnancy following SET cycles	53 130	230	53 360
Rate of SET cycles (%)	82.7	77.2	82.7
Pregnancy rate following SET cycles (%)	34.3	27.1	34.3
Miscarriages	16 552	84	16 636
Miscarriage rate per pregnancy (%)	26.5	28.6	26.5
Singleton pregnancies[Link]	59 472	257	59 729
Multiple pregnancies[Link]	2020	12	2032
Twin pregnancies[Link]	1979	11	1990
Triplet pregnancies[Link]	38	1	39
Quadruplet pregnancies[Link]	3	0	3
Multiple pregnancy rate (%)[Link]	3.3	4.5	3.3
Live births	43 153	176	43 329
Live birth rate per FET (%)	23.1	16.0	23.0
Total number of neonates	44 484	178	44 662
Singleton live births	41 615	170	41 785
Twin live births	1412	4	1416
Triplet live births	15	0	15
Quadruplet live births	0	0	0
Pregnancy outcomes
Ectopic pregnancies	357	2	359
Intrauterine pregnancies coexisting with ectopic pregnancy	1	0	1
Artificial abortions	277	1	278
Stillbirths	175	2	177
Fetal reduction	23	1	24
Unknown cycles for pregnancy outcomes	1702	11	1713

FET, frozen‐thawed embryo transfer; SET, single embryo transfer.

Including cycles using frozen‐thawed oocyte.

Singleton, twin, triplet and quadruplet pregnancies were defined according to the number of gestational sacs in utero.