Abstract
The examination of fetal pulmonary function in cases of antenatally diagnosed congenital diaphragmatic hernia may become very important in defining optimal postnatal management strategies and to improve survival in these infants. Antenatal prediction of pulmonary insufficiency in cases of congenital diaphragmatic hernia can be appropriately done only with a clear understanding of of fetal respiratory pathophysiology. The article is dedicated to the studying of fetal respiratory physiology and new method for measuring timing parameters of fetal breathing cycle in human fetuses. It is well known that the fetal upper respiratory tract plays an important role in the maintaining lung volume and flow of lung liquid from the fetal airways. Such observations in humans were performed in 1993, after Doppler techniques were applied to the fetal upper respiratory tract. At that time we studied fetal perinasal fluid flow in cases of congenital diaphragmatic hernia to determine the degree to which the nasal flow is related to the development of diaphragmatic muscles. This information was used in the future research to investigate the fetal respiratory function and develop the current management of the intrauterine treatment in cases of congenital diaphragmatic hernia.