Fetal adaptation to stress. Part I: acceleration of fetal maturation and earlier birth triggered by placental insufficiency in humans.

This review is an attempt to provide an integrative view for the biological changes triggered by fetal stress through a multidisciplinary approach. Acceleration of brain and lung maturation in certain risk pregnancies was first described clinically and confirmed by biochemical, electrophysiological and experimental data. Moreover, new experimental findings suggest that a fetal clock centrally mediated by fetal nutritional status could determine timing of parturition. However, some skepticism persisted about the usefulness of this body of knowledge for obstetrical management in developed countries. The interest concerning this adaptation to intrauterine stress was later renewed from various sources, as developed in Part II.