ABSTRACT
This chapter explores the relationship between the quantity of amniotic fluid and the growth of the fetal lung. W. A. Blanc had noted that oligohydramnios due to the leakage of amniotic fluid caused lung hypoplasia. Theories include altered dynamics of fetal lung fluid, abnormal fetal breathing, and fetal compression. Breathing movements involve both an influx of amniotic fluid and an ultimate net outflow of lung fluid. The chapter explains animal models of lung hypoplasia caused by the leakage of amniotic fluid. The initial animal used was the rat to confirm that an animal could be used to reproduce the observation made in humans. The importance of the quantity of fetal lung fluid has been shown in experiments in which ligating the fetal lamb trachea to prevent the egress of lung fluid causes enlargement of the fetal lungs, whereas draining the lung fluid cause lung hypoplasia.
