The authors have studied newborn weight and placentas pregnancies from Puno, Peru at an altitude of 3850 m.; as studied 46 normal pregnancies from different hospitals in from 46 normaI control group they Lima at 150 m. The newborn weights were similar in both places, however, placental weight and volume were higher in Puno, so the placental coefficient was higher in altitude. The macroscopic analysis in terms of parenchimal and non parenchimal tissue was not different in both groups, but the microscopic analysis showed richer capillarity with diminished villous in Puno. No differences were appreciated in the proportion of trophoblastic ephithelium. The total area of the chorial villous and capillary surface were significantly major in altitude. The authors postulate these morphologic changes favor the metabolic placental exchange in the hypoxic environment of high altitude.

The authors have studied newborn weight and placentas pregnancies from Puno, Peru at an altitude of 3850 m.; as studied 46 normal pregnancies from different hospitals in from 46 normaI control group they Lima at 150 m. The newborn weights were similar in both places, however, placental weight and volume were higher in Puno, so the placental coefficient was higher in altitude. The macroscopic analysis in terms of parenchimal and non parenchimal tissue was not different in both groups, but the microscopic analysis showed richer capillarity with diminished villous in Puno. No differences were appreciated in the proportion of trophoblastic ephithelium. The total area of the chorial villous and capillary surface were significantly major in altitude. The authors postulate these morphologic changes favor the metabolic placental exchange in the hypoxic environment of high altitude.

It has conducted a quantitative study of electronic 3 placentas of Cerro de Pasco micrographs (height, 4,330 m.), 4 placentas of Puno (3,850 m.) And 4 placentas of Lima (150 m.). It has been determined that the area of the villous surface determined by light microscopy is increased due to the presence of microvillos by a factor of 5.23 in Cerro de Pasco, Puno 3.50 and 3.03 in Lima (mean values). As a result, the area of maternal-fetal exchange is of 60.72 m2 in Cerro de Pasco, Puno 38.92 m2 and 26.60 m2 in Lima. The finding is interpreted as an adaptive mechanism of the placenta in height to the situation of hypoxia, to favor the phenomena of maternal-fetal exchange. Simple linear measurements of the thickness of the placenta showed no difference between groups in height and sea level. Because of the relative character of the measurement is not discarded, real differences with other meas...

It has conducted a quantitative study of electronic 3 placentas of Cerro de Pasco micrographs (height, 4,330 m.), 4 placentas of Puno (3,850 m.) And 4 placentas of Lima (150 m.). It has been determined that the area of the villous surface determined by light microscopy is increased due to the presence of microvillos by a factor of 5.23 in Cerro de Pasco, Puno 3.50 and 3.03 in Lima (mean values). As a result, the area of maternal-fetal exchange is of 60.72 m2 in Cerro de Pasco, Puno 38.92 m2 and 26.60 m2 in Lima. The finding is interpreted as an adaptive mechanism of the placenta in height to the situation of hypoxia, to favor the phenomena of maternal-fetal exchange. Simple linear measurements of the thickness of the placenta showed no difference between groups in height and sea level. Because of the relative character of the measurement is not discarded, real differences with other meas...