MIDDLE CEREBRAL ARTERY / UMBILICAL ARTERY RATIO

Workers have reported that the cerebral umbilical artery ratio may be useful for identifying fetuses with increased placental vascular resistance, decreased cerebral vascular resistance or both.

• Umbilical artery / internal carotid artery ratio:
• Sensitivity of 70% for identifying growth-retarded fetuses (sensitivity of 60% for the internal carotid artery alone and 48% for the umbilical artery alone) (1).
• Cut off value of 1 after 30 weeks gestation (and remained constant until term) (2).
• Accuracy = 90%
• Accuracy of umbilical artery (83%) and MCA (78.8%) when used alone.
• Differences were not significantly different (probably due to the small number of fetuses studied).

• Umbilical artery to middle cerebral artery ratio (Table)–Arduini et.al. 1992
• Umbilical artery to middle cerebral artery ratio (Graph)–Arduini et.al. 1992

REFERENCES

1. Wladimiroff JW, van den Wijngaard JAG, Degani S et.al. Cerebral and umbilical arterial blood flow velocity waveforms in normal and growth retarded pregnancies: A comparative study. Obstet Gynecol 1987;69:705-709.
2. Gramellini D, Folli MC, Raboni S et.al. Cerebral - umbilical doppler ratio as a predictor of adverse perinatal outcome. Obstet Gynecol 1992;79:416-420.