The most common type of growth abnormality demonstrating normal cranial growth and a decrease in abdominal growth is:

The most common type of growth abnormality demonstrating normal cranial growth and a decrease in abdominal growth is:

• A. Asymmetric IUGR
• B. Symmetric IUGR
• C. Macrosomia
• D. Post-term pregnancy

Answer: (A)

In asymmetric IUGR, placental insufficiency tends to occur later in pregnancy, so the fetus redistributes blood flow to protect the brain. This brain-sparing effect allows head growth to remain normal while the abdomen lags behind, giving normal cranial measurements with a decreased abdominal circumference. This pattern is the most common way growth abnormalities present when the fetus is growth-restricted due to late-onset placental problems. By contrast, symmetric IUGR results from an early insult and shows proportionally small head and body measurements. Macrosomia is when the fetus is larger than normal, and post-term pregnancy describes gestational length beyond term, not the specific cranial-abdominal growth discrepancy described here.

In asymmetric IUGR, placental insufficiency tends to occur later in pregnancy, so the fetus redistributes blood flow to protect the brain. This brain-sparing effect allows head growth to remain normal while the abdomen lags behind, giving normal cranial measurements with a decreased abdominal circumference. This pattern is the most common way growth abnormalities present when the fetus is growth-restricted due to late-onset placental problems. By contrast, symmetric IUGR results from an early insult and shows proportionally small head and body measurements. Macrosomia is when the fetus is larger than normal, and post-term pregnancy describes gestational length beyond term, not the specific cranial-abdominal growth discrepancy described here.