1. case report
At the outset, a 36-year-old pregnant woman without consanguineous history was suspected absent pulmonary valve syndrome (APVS) in fetus in the first trimester screening in our Hospital. The pregnancy is natural with no history of fever, discomfort, allergies and medication in early period. The biological parameters were in accordance with those of 13th gestational weeks. Fetal nuchal translucency (NT) was in normal range(0.19cm), the pulsed doppler spectrum of ductus venosus (DV) was normal in shape. The blood flow through mitral valve and tricuspid valve in the 4-chamber view was symmetrical. However, in the 3-vessel tracheal view, there were anterograde blood flows in systole and retrograde blood flow in diastole in pulmonary artery (PA) and patent ductus arteriosus (PDA), which suggested absent of pulmonary valve. Due to the obesity and rejection of transvaginal examination of the patient, a meticulous fetal heart examination was arranged 7 days later and more positive results were found: bidirectional blood flow in the upper segment of interventricular septum (beam width 0.14 cm); overriding aorta; narrowed pulmonary valve annulus with pulmonary valve unexplored; moderate reflux flow of tricuspid valve. To-and-from blood flow was detected clearly through pulmonary annulus, PA trunk, left pulmonary artery (LPA), right pulmonary artery (RPA) and PDA. By these features, APVS with tetralogy of Fallot (TOF) was diagnosed (Figure 1). The shape and size of PA trunk, PA branches and PDA still seemed normal.
The fetus was reexamined 15 days later. The biparietal diameter (BPD) was 3.2cm and femoral diameter (FL) was 1.9cm, which were consistent with 16 weeks of pregnancy. The right heart was slightly larger than left heart in 4-chamber view, the width of ventricular septal defect (VSD) was 0.17cm. The diameter of aortic annulus riding over the VSD was 0.24 cm. Pulmonary valve leaflets were undetectable during dynamic observation. The diameters of pulmonary valve annulus, pulmonary trunk, LPA, RPA, DA were clearly measured as 0.16cm, 0.23cm, 0.19cm, 0.20cm, 0.13cm respectively. The ectasia of pulmonary trunk and branches combined with the stenosis of annulus constituted a distinct ”goldfish tail sign”. Despite of the to-and-fro flow, the blood flow mosaic was detected in pulmonary trunk which proved the acceleration of flow through pulmonary valve annulus. DA was much narrower than pulmonary trunk and branches with comparatively dim blood flow through, suggesting the restriction of DA with decreased blood flow (Figure 2). Except for fetal cardiac anomalies, left renal cyst (0.4 × 0.4cm) was found in fetus with normal amniotic fluid.
Approved by the ethics committee of our hospital, fetal induction was performed. Fetal autopsy approved by the pregnant mother confirmed the diagnosis of APVS with TOF by fetal echocardiography (Figure 3). Chromosome microarray chip analysis (CMA) showed that the 984.766kb fragment at 20p12.2 deleted.