Читать книгу Protocols for High-Risk Pregnancies - Группа авторов - Страница 68

Fetuses that fail to reach their genetically determined growth potential due to uteroplacental dysfunction may develop abnormal resistance to blood flow in the placenta. This abnormal resistance is due to numerous placental vascular abnormalities (poor villous capillarization, reduced number and branching of stem arteries, luminal reduction, and wall hypertrophy), which can be detected with Doppler velocimetry in the umbilical artery located upstream from the placenta. Progression of placental disease with concomitant worsening of blood flow resistance may lead to additional Doppler velocimetry changes in the central nervous system, and eventually in the precordial venous system or the heart. Once the fetus decompensates to that level of Doppler abnormality, acidemia is nearly always present.