engleski

The flow redistribution toward the brain: beneficial and adverse effects on the fetal outcome in hypertensive pregnancies

Objective: To predict fetal outcome (abnormal FHR to cerebral lesion) from the degree and the duration of the hypoxia. Method: Pregnancies complicated with hypertension and IUGR were submitted to a daily umbilical and cerebral Doppler from first day of admission until delivery. The umbilical (URI), and cerebral (CRI) resistance indices, cerebral-umbilical ratio (C/U=CRI/URI), and the hypoxia index (HI) were calculated. The HI expresses as the maximum C/U change between admission day and delivery day (in percentage of C/U at admission, or in percentage of C/U cut-off limit (=1) if C/U admission < 1) multiplied by number of days of observation. Results: 68 pregnancies investigated (age: 25 +- 5 years, primipar: 35%, admission date: 30.8 +- 2.5 weeks, delivery at 33.2 +- 2.8, mean weight: 2300 +- 457g. The combination (HI > 200 and C/U < 1) was associated with abnormal FHR in 75% cases, whereas 1 or 2 of these parameter normal was associated with normal FHR in 85% cases (PPV 75% - NPV 85%). The minimal C/U and the HI during the period of observation allowed to predict abnormal FHR at delivery. On 5 pregnancies the period of hypoxia extended over 10-20 days (C/U << 1, HI >> 200), the fetuses died or were handicaped at delivery. The daily cerebral index recording showed a loss of fluctuation from one day to another, which could correspond to a deterioration of the cerebral regulation (vasoplegia). We suggest that the loss of fluctuation could be considered as the last limit beforethe cerebral lesion have serious chances to develop. In these 5 cases the fetal heart rate abnormalities appeared several days after this limit was passed.

fetal hypoxia; hypoxia index; fetal outcome

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