WS15-06Doppler ultrasonography of the human fetal pulmonary circulation and its role in the prediction of pulmonary hypoplasia

Objectives To determine the value of Doppler flow velocity waveforms from the fetal arterial pulmonary branches relative to fetal biometric indices and clinical correlates in the prenatal prediction of lethal lung hypoplasia (LH) in prolonged oligohydramnios. Study design 42 singleton pregnancies with oligohydramnios associated with premature rupture of membranes (PROM, n = 31) or bilateral renal pathology (n = 11) were examined using a combined color coded Doppler and 2d real-time ultrasound system. Thoracic (TC), cardiac (CC) and abdominal circumference (AC) and the largest vertical amniotic fluid pocket were measured. Pulsed Doppler measurements of the arterial pulmonary branches were made at the level of the cardiac four-chamber view after visualization with color Doppler. Diagnosis of LH was based on pathological, clinical and radiological criteria. Results The prevalence of lethal LH was 43%. In the PROM-subset, combination of onset of PROM = 20 weeks; duration of oligohydramnios = 8 weeks and degree of oligohydramnios = 1 cm, presented the highest clinical prediction rate for lethal LH. For both the total group and the PROM-subset, the highest prediction rate for lethal LH from biometric and Doppler parameters was presented by TC/AC ratio, peak systolic velocity in the proximal branch and time-averaged and end-diastolic velocity in the middle branch of the pulmonary artery. In the prom subset, combination of all three clinical, biometric and Doppler parameters revealed the most favorable combination to predict lethal LH (PPV 100%, accuracy 93%, and sensitivity 71%). Conclusion Doppler velocimetry may detect changes in blood velocity waveforms from the arterial branches of the fetal pulmonary circulation in the presence of LH, but fails to be the ultimate test for the prenatal prediction of lethal LH. The best prediction can be achieved by combining clinical, biometric and Doppler parameters.