Fresh embryo transfer group N=1822
Frozen-thawed embryo transfer group N=2098
Frozen-thawed embryo transfer group N=2098
Frozen-thawed embryo transfer group N=2098
χ2/U value
P value
χ2/U value*
P value*
NC-FET group N=1353 HRT-FET group N=745
Total
Gestational age(week) 39.14(38.29,40.00) 39.14(38.43,40.14) 39.14(38.21,40.14) 39.14(38.29,40.14) 2.77 0.25 -1.47 0.141
Preterm birth 140(7.7%) 103(7.6%) 78(10.5%) 181(8.63%) 6.37 0.041 1.15 0.283
24-27+6week 7(5.00%) 7(6.80%) 2(2.56%) 9(4.97%) 7.99 0.239 3.65 0.310
28-31+6week 26(18.57%) 10(9.71%) 15(19.23%) 25(13.81%) Ref Ref Ref Ref
32-33+6week 14(10.00%) 18(17.48%) 12(15.38) 30(16.57%) Ref Ref Ref Ref
34-36+6week 93(66.43) 68(66.02%) 49(62.82%) 117(64.64%26) Ref Ref Ref Ref
Placental weight 520(500,600) 520(500,600) 540(500,600) 530(500,600) 4.50 0.106 -2.00 0.046
Preeclampsia 100(5.49%) 80(5.91%) 100(13.42%) 180(8.58%) 54.90 <0.001 14.05 <0.001
Preeclampsia 52(2.85%) 37(2.73%) 48(6.44%) 85(4.05%)
23.74
<0.001
4.15
0.042
Severe preeclampsia 48(2.63%) 43(3.18%) 52(6.98%) 95(4.53%)
29.70
<0.001
9.95
0.002
Gestational hypertension 47(2.58%) 34(2.51%) 43(5.77%) 77(3.67%) 20.44 <0.001 3.79 0.052
Early-onset preeclampsia 36(1.98%) 28(2.07%) 32(4.30%) 60(60/180) 13.15 0.001 3.19 0.074
Gestational diabetes mellitus 583(32.0%) 436(32.2%) 236(31.7%) 672(32.03%) 0.07 0.967 0.000 0.983
Type A1 544 388 209 597
Type A2 39 48 27 75
Cervical insufficiency 39(2.1%) 37(2.7%) 33(4.4%) 70(3.34%) 10.27 0.006 5.16 0.023
Postpartum haemorrhage 221(12.1%) 149(11.0%) 162(21.7%) 311(14.82%) 53.21 <0.001 6.03 0.014
uterine inertia 163 122 124 246
placental factors 46 27 44 71(22.83%)
placenta increta 20 7 20 27
placenta accreta 12 9 17 26
Placenta previa 14 11 7 18
Soft birth canal laceration 10 7 14 21
Coagulation dysfunction 0 1 2 3
Mode of delivery 57.30 <0.001 12.88 <0.001
Vaginal delivery 985(54.1%) 714(57.0%) 300(40.3%) 1014(48.33%)
Caesarean section 837(45.9%) 639(43%) 445(59.7%) 1084(51.67%)