This thesis presents the extensive research on Doppler ultrasonography of the arterial and venous lung circulation in the normally developing human fetus and in the fetus at risk for lung hypoplasia. The results improve our understanding of fetal pulmonary hemodynamics under physiological conditions.
Since lung hypoplasia is associated with a high perinatal mortality rate, an accurate prenatal test for detecting this underdevelopment is highly desirable. Morphological changes in the lung vascularization associated with lung hypoplasia, could effect pulmonary blood flow and consequently induce changes in pulmonary blood flow velocity waveforms as recorded by Doppler ultrasonography. The value of Doppler velocimetry of the fetal arterial pulmonary ciculation in the prenatal prediction of lung hypoplasia due to prolonged oligohydramnios, has been evaluated and compared with other methods.