OBJECTIVES

To establish normal reference intervals of fetal regional brain blood perfusion using power Doppler ultrasound as measured by fractional moving blood volume (FMBV).

METHODS

A cohort of consecutive singleton normally grown fetuses was selected including at least 12 fetuses for each completed week of gestation between 24 and 41 weeks. Cerebral blood perfusion was estimated using conventional power Doppler ultrasound in the following brain regions: frontal area, basal ganglia and posterior brain. Five consecutive good-quality images were recorded in each area and the region of interest was delineated offline. The FMBV was quantified as the average of all images and expressed as a percentage. Normal reference ranges were constructed by means of the LMS (lambda-mu-sigma) method.

RESULTS

A total of 230 fetuses were included. The median gestational age at evaluation and at delivery was 33.1 (range, 24.0-41.0) and 39.7 (range, 34.9-42.3) weeks, respectively. From 24 to 41 weeks' gestation, the mean FMBV increased from 13.21 to 14.97% in the frontal area, 11.17 to 14.86% in the basal ganglia and 4.83 to 6.70% in the posterior brain.

CONCLUSIONS

Normal data of fetal cerebral blood perfusion in the frontal area, basal ganglia and posterior brain are provided, which could be of clinical use in the assessment of fetal brain circulation.