RESUMO
Objective The purpose of this study was to produce cut-off values of fetal pulmonary artery stenosis (PS),allowing the application of Z-scores to evaluate fetal pulmonary artery.Methods A total of 214 normal singleton fetuses and 107 singleton fetuses with PS were included in this study.They were measured for standard biometry:biparietal diameter (BPD) and femoral diaphysis length (FL) and an assessment of gestation age (GA).The standardized fetal echocardiographic measurements included diameters of pulmonary valve annulus (PV),pulmonary artery (PA),ductus arteriosus (DA) and aorta (AO).Then we calculated the Z-scores from parameters of fetal size.The Z-scores differences of PV,PA,DA and AO in PS group were compared.The receiver operator characteristic (ROC) curves of PV and PA Z-scores were obtained by statistical analysis.Results Compared with the normal group,the Z-scores of PV,PA and DA decreased in the PS group,whereas the Z-scores of AO increased (P ＜0.01 for all).The critical values of Z-score for PV in diagnosing PS with BPD,FL and GA as variables were-1.13,-1.33,-1.28,with sensitivity 94.2％,90.3％,93.5％,specificity 60.0％,65.0％,62.5％,respectively.The critical values of Z-score for PA with BPD,FL and GA as variables were-1.01,-0.98,-1.01,with sensitivity 96.8％,96.8％,96.1％,specificity 65.0％,65.0％,62.5％,respectively.Conclusions In the fetus with pulmonary artery stenosis,PV,PA and DA Z-scores decreased,while AO Z-scores increased.The pulmonary artery Z-scores had important application value in quantitative evaluation and diagnosis of mild fetal pulmonary artery stenosis.