engleski

Doppler Assessment of The Fetal Brain Response to Hypoxia

The cardiovascular adaptation to hypoxia, which is important for maintenance of fetal homeostasis, is manifested by redistribution of blood flow, primarily toward the fetal brain. Our preliminary results indicate that during the development of fetal hypoxia a loss of cerebrovascular reactivity occurs (ability for further vasodilatation) remarkably before the changes in fetal heart rate (Salihagić A et al,1996). The disappearance of cerebral vascular response could identify the beginning of the period of a very high risk for the fetus. Indeed, a recent work has shown that brain damage can develop despite the existence of redistribution. This leads to a question of redistribution as a purely physiological phenomenon. By monitoring cerebrovascular reactivity we tried to determine what reduction in the cerebral-umbilical ratio (i.e. p02) remains acceptable for fetal brain, and for what duration. Thus, a boundary between physiological and pathological processes which cause brain damage would be determined for the first time by noninvasive method (color Doppler). Introduction of a new, vascular score in assessment of the beginning of the period of a very high risk for the fetus, according to changes in brain vascular reactivity since brain responds first and is the most sensitive to hypoxia, would represent a significant advance in prevention of hypoxic lesions. And it is the hypoxic lesions that are one of the most frequent causes of perinatal morbidity and mortality.

fetal hypoxia; Doppler assessment; growth-retarded fetus

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