Comprehensive fetal assessment with three ultrasonographic characteristics

When three ultrasonographic characteristics--umbilical artery Doppler recording, growth (abdominal circumference), and biophysical profile score--are used in combination in assessment of fetuses at risk of chronic asphyxia: (1) What are the order and time scale for the development of abnormality with each characteristic? (2) What is the short-term outcome associated with abnormalities of the three characteristics? (3) Should we amend our fetal assessment protocol?

An audit of 103 fetuses (100 mothers) referred to a tertiary center for fetal assessment because of suspected chronic fetal asphyxia was performed with three ultrasonographic characteristics, umbilical artery Doppler recording, measurement of abdominal circumference, and documenting the biophysical profile score.

The order of deterioration (which had a very variable time scale) was umbilical artery Doppler recording, followed by abdominal circumference and finally biophysical profile score. Normal characteristics or an abnormal umbilical artery Doppler recording alone or an abnormal abdominal circumference alone was associated with an excellent prognosis. The worst outcome was found in the 28 fetuses with abnormality of all three ultrasonographic features before delivery.

The main suggested implications for management are avoidance of preterm delivery with normal ultrasonographic characteristics, an abnormal umbilical artery Doppler recording alone, or an abnormal abdominal circumference alone; delivery of fetuses at greater than or equal to 34 weeks with abnormal umbilical artery Doppler recording and abdominal circumference before the biophysical profile score becomes abnormal; and implementation of specific measures to prevent necrotizing enterocolitis in newborns when all three characteristics are abnormal.