ULTRASOUND DIAGNOSIS OF IUGR

1. Fetal morphometric indices.
• Fetal age determination.
• BPD, HC.
• AC.
• Femur length.
• Humerus, ulna, radius, tibia, fibula (Tables / Graphs)
• Normal Transcerebellar Diameter (Table / Graph)
• Ratio of HC/AC.
• Fetal mass determination.
• Fetal proportions (symmetrical versus asymmetrical).
2. Amniotic fluid volume.
3. Fetal fat distribution.
4. Fetal biophysical profile scoring.
5. Placental assessment.
6. Doppler blood flow velocity waveforms.
7. Categories based on estimated fetal weight and umbilical artery S/D ratio (1)
• Umbilical artery RI/PI - Increases.
• Descending aorta RI/PI - Increases. 1. Group 1: AGA fetuses with normal S/D ratio.
• Renal artery RI/PI - Increases. 2. Group 2: AGA fetuses with abnormal S/D ratio (above 90^th
• Cerebral arteries RI/PI - Decreases. centile 90^th centile for GA). Increased neonatal morbidity.
• Adrenal artery RI/PI - Decreases. 3. Group 3: SGA fetuses with normal doppler studies - Outcome
• Coronary artery RI/PI - Decreases. the same as AGA cohorts
• Splenic artery RI/PI - Decreases. 5. Group 4: SGA fetuses with abnormal doppler studies –.
• Peripheral pulmonary artery RI/PI - Increases. Increased perinatal mortality
8. Fetal compensation:
• “Brain sparing effect”. MCA RI / UA RI < 1 (normally > 1).

IUGR with fetal compensation (“brain-sparing” effect) Middle cerebral artery / Umbilical artery Ratio = 0.64 / 0.84 = 0.76 Normal = > 1

· Increased blood flow to myocardium (dilated coronary arteries)

Video clip of IUGR - Centralization of fetal blood flow Video clip of IUGR - Absent end-diastolic flow in the umbilical artery

8. Cardiac and other hemodynamic changes.

REFERENCES

1. Ott WJ. Intrauterine growth restriction and doppler ultrasonography. J Ultrasound Med 2000;19:661-665.