Quantitative morphology of the placenta. III. The growth of the placenta and its relationship to birth weight.
The relationship of placental components to birth weight was investigated by stereology. 37 placentas from nonpathological pregnancies delivered after a period of 224-303 days of amenorrhea were examined. The umbilical cord was clamped immediately after birth. The ratios of the volume, the surface, the length of the villous vessels and the surface of the villi with birth weight showed a decrease after 277 days of amenorrhea. In contrast to this decrease, the ratio of the volume of the trophoblast with birth weight seems to increase. No difference could be found for the ratios of the placental volume (placental index), the volume of the villous tissue, the volume of the intervillous space and the volume of the nonfunctional tissue with birth weight. These ratios reveal a quantitative morphological base for the clinical experience that postmature fetuses are at a higher risk through deterioration of the placenta.
D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D010920:Placenta / Q000033:anatomy & histology*; D011247:Pregnancy; D012044:Regression Analysis