Fresh embryo transfer group N=197
Frozen-thawed embryo transfer group N=324
Frozen-thawed embryo transfer group N=324
Frozen-thawed embryo transfer group N=324
χ2/U value
P value
χ2/U value*
P value*
NC-FET group N=175 HRT-FET group N=149
Total
Chorioamnionitis 129(65.6%) 122(69.7%) 82(55.5%) 204(62.96%) 7.86 0.020 0.34 0.561
infarction 47(23.9%) 45(25.7%) 29(19.5%) 74(22.84%) 1.84 0.400 0.07 0.790
Calcification 55(27.9$) 57(32.6%) 46(30.9%) 103(31.79%) 0.98 0.613 0.87 0.351
Interstitial haemorrhage 11(5.6%) 7(4.0%) 2(1.3%) 9(2.78%) 4.15 0.125 2.61 0.106
Syncytiotrophoblastic nodule hyperplasia 4(2.0%) 5(2.9%) 4(2.7%) 9(2.78%) 0.29 0.865 0.06 0.810
Fibrin deposition 4(2.0%) 4(2.3%) 3(2.0%) 7(2.16%) 0.04 0.981 0.00 1.000
Chorionic villus infarction 1(0.5%) 5(2.9%) 6(4.0%) 11(3.40%) 5.03 0.081 Ref 0.036#