Maternal plasma glucose levels and Doppler flow velocity waveforms in cerebral arteries of growth-retarded fetuses.

Abstract

Doppler flow studies of the intracranial internal carotid artery and middle cerebral artery performed in 17 women at 30-36 weeks of gestation, referred for evaluation of small for gestational age fetuses, resulted in abnormally low pulsatility index values (below 2 SD). These patients were investigated when fasting and 1 h after a 100-gram glucose load. Increase of 20 ml/dl or more was followed by elevation of the mean pulsatility index in the internal carotid artery from 1.03 +/- 0.09 to 1.44 +/- 0.22 (p < 0.001), and in the middle cerebral artery from 1.12 +/- 0.16 to 1.83 +/- 0.24 (p < 0.001). Pulsatility index values returned to normal (within 2 SD for gestational age) in 15 of the subjects investigated after glucose load. These findings suggest the importance of standard fasting state or determination of maternal plasma glucose levels in patients undergoing Doppler flow evaluation of growth-retarded fetuses.