Browsing by Autor "Postigo, Lucrecia"

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Índice de resistencia vascular arterial en la madre y el feto durante el embarazo en grandes alturas (3600 m) vs. niveles bajos de altura (300 m)
(Facultad de Medicina, Enfermería, Nutrición y Tecnología Médica, 2007) Postigo, Lucrecia
Resumen. Objetivo: Determinar los índices de resistencia de las arterias uterinas en las madres, umbilical y cerebral media en los bebés de grandes alturas, en comparación a pacientes que habitan alturas bajas reflejados en los valores de hemoglobina y hematócrito y la viscosidad de la sangre. Diseño de Estudio: Es un estudio prospectivo de la fisiología del parto en mujeres embarazadas que viven en las zonas altas vs. zonas bajas en Bolivia. Se realizaron estudios Doppler para determinar los índices de resistencia y factores hematológicos que puedan causar elevación de resistencia y menor flujo de sangre. Resultados: Se estudiaron 85 embarazadas a 3600 m y 70 habitantes a 300m.s.n.m. (sobre el nivel del mar)y se obtuvo los siguientes resultados: en las habitantes de 300 m se encontró que el promedio...
Where the O2 goes to : preservation of human fetal oxygen delivery and consumption at high altitude
(Facultad de Medicina, Enfermería, Nutrición y Tecnología Médica, 2009) Postigo, Lucrecia
Fetal growth is decreased at high altitude (> 2700 m). We hypothesized that variation in fetal O2 delivery might account for both the altitude effect and the relative preservation of fetal growth in multigenerational natives to high altitude. Participants were 168 women of European or Andean ancestry living at 3600 m or 400 m. Ancestry was genetically confirmed. Umbilical vein blood flow was measured using ultrasound and Doppler. Cord blood samples permitted calculation of fetal O2 delivery and consumption. Andean fetuses had greater blood flow and oxygen delivery than Europeans and weighed more at birth, regardless of altitude (+208 g, P < 0.0001). Fetal blood flow was decreased at 3600 m (P < 0.0001); the decrement was similar in both ancestry groups. Altitude-associated decrease in birth weight was greater in Europeans (−417 g) than Andeans (−228 g, P < 0.005). Birth weight at 3600 m was > 200 g lower for Europeans at any given level of blood flow or O2 delivery. Fetal haemoglobin concentration was increased, P CO2 decreased, and the fetal P O2/SO2 curve was left-shifted at 3600 m. Fetuses receiving less O2 extracted more (r2 = 0.35, P < 0.0001). These adaptations resulted in similar fetal O2 delivery and consumption across all four groups. Increased umbilical venous O2 delivery correlated with increased fetal O2 consumption per kg weight (r2 = 0.50, P < 0.0001). Blood flow (r2 = 0.16, P < 0.001) and O2 delivery (r2 = 0.17, P < 0.001) correlated with birth weight at 3600 m, but not at 400 m (r2 = 0.04, and 0.03, respectively). We concluded that the most pronounced difference at high altitude is reduced fetal blood flow, but fetal haematological adaptation and fetal capacity to increase O2 extraction indicates that deficit in fetal oxygen delivery is unlikely to be causally associated with the altitude- and ancestry-related differences in fetal growth.