engleski

Doppler monitoring of the fetal brain response to chronic hypoxia

Objective: To study the cerebral and umbilical hemodynamics changes in growth-retarded fetuses with chronic hypoxia and to determine if at long term, fetal brain hyperperfusion with loss of cerebral vascular flow velocity variability is associated with brain damage. Methods: The cerebral and umbilical hemodynamics was assessed by Doppler in 6 growth-retarded and hypoxic fetuses, mainly every day during 11 to 21 days. Results: All 6 fetuses had poor fetal outcome including fetal death (3). Fetal flow redistribution with brain hyperperfusion was present in all 6 fetuses during the whole period of observation. The fetal deterioration was characterised by: (1) the progressive development of oligohydramnios ; (2) the disappearance of the cerebral flow velocity variability during the early phase of deterioration ; (3) the occurrence of fetal heart rate decelerations ; and finally (4) the increase of cerebral vascular resistance with reduction of brain perfusion during the later phase of deterioration. The histology of three brains revealed hypoxic lesions. Conclusion: The decrease in cerebral-umbilical ratio during 11 to 21 days, which correspond to a sustained hypoxia with increased brain perfusion and the loss of cerebral flow variability were associated in all cases with severe fetal outcome.

fetal hypoxia ; growth retardation ; Doppler

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