Doppler assessment of umbilical artery, thoracic aorta and middle cerebral artery in the management of pregnancies with growth restriction.

ABSTRACT

BACKGROUND: The aim of the study was to determine the best use of information obtained from Doppler studies of umbilical artery, thoracic aorta and middle cerebral artery in the management of pregnancies with growth restriction. METHODS: The study group consisted of 100 pregnant women with intrauterine growth restricted fetuses. Doppler flow velocity waveforms were obtained from the umbilical artery, middle cerebral artery and thoracic aorta. The pregnancies were grouped according to the umbilical artery Doppler results. There were 29, 30 and 41 fetuses with normal and high PI (pulsatility index), and absent end-diastolic velocity (AEDV) in the umbilical artery, respectively. RESULTS: Birth weight and umbilical vein pH at birth significantly decreased and perinatal mortality rates significantly increased with the worsening of the diastolic flow in the umbilical artery (p<0.01). Increased umbilical artery PI was significantly associated with increased thoracic aorta PI and decreased middle cerebral artery PI (r=0.75 and -0.55, p<0.01 respectively). Perinatal mortality due to fetal asphyxia in fetuses with AEDV in the umbilical artery and in both the umbilical artery and thoracic aorta was 39.5% and 50%, respectively. Detection of AEDV in the thoracic aorta was found to be the most significant predictive factor of perinatal deaths. CONCLUSIONS: The degree of abnormality of the Doppler findings parallels the severity of fetal compromise. Growth restricted fetuses with AEDV detected both in the umbilical artery and thoracic aorta are severely compromised and time gained in utero has no benefit for these fetuses.