The effects of placental insufficiency on the fetal lung.

Any discussion of this subject 10 to 15 years ago would of necessity have been limited to morbid anatomical concepts with descriptions mainly of inhaled amniotic debris and the possible prenatal origin of hyaline membrane disease (HMD). With the advances in knowledge of fetal pulmonary physiology, the production and absorption of lung liquid, surfactant synthetic pathways and fetal breathing movements, we are now in a position to consider the possible effects of placental insufficiency in terms of altered fetal pulmonary physiology. In this paper I propose to consider how placental insufficiency may impinge on the functional activities of the developing lung and how this may affect adaptation to extrauterine respiration. I intend to be thoroughly provocative and to use available evidence to construct a tenuous hypothesis of my own on the mechanisms responsible for normal control of fetal lung growth and the triggering of biochemical lung maturation.