The human placenta. Anatomy and morphology.

This review presents basic aspects of placental morphology with particular reference to the regional specialization of human placental tissues. Intrauterine visualization of the placenta is now possible with new non-invasive methods. Echotomographic ultrasound images of the placenta in vivo and in vitro are of the greatest value for clinical and pathological diagnosis. X-ray computed tomography, though it cannot be applied to pregnant women, is invaluable for the study of circulatory and pathologic changes in the placenta isolated post partum. Nuclear magnetic resonance imaging is another useful adjunct not only for placental localization but also to detect changes of placental morphology with an accuracy almost as good as ultrasonography. Fourier-transform spectroscopy now offers a unique opportunity to obtain computed biochemical data on the metabolic evolution of the human placenta.