Symmetric IUGR indicates a fetus that is small in which pattern?

• A. Proportionally small across measurements
• B. Head larger than body
• C. Abdomen larger than head
• D. Only limb length is reduced

Answer: (A)

Symmetric IUGR is when the fetus is small in all biometric measurements, meaning head circumference, abdominal circumference, biparietal diameter, and femur length are reduced by similar amounts. This pattern shows a global restriction that starts early in pregnancy, so the entire fetus grows together rather than one part being spared or emphasized. Because both the head and body are reduced proportionally, the head-to-abdomen relationship stays roughly normal.

This differs from patterns where one area is relatively preserved or disproportionately small. For example, if the abdomen is disproportionately small compared with the head, that points to late-gestation placental insufficiency and asymmetric IUGR, often described as head-sparing. So the scenario in which the fetus is small across measurements best captures symmetric IUGR.